Manufacturing method for shaped article

ABSTRACT

A manufacturing method for a shaped article is provided. The shaped article comprising: a decorative layer; a first transparent layer; and a light reflective layer, being formed from an ink having light reflectiveness. The decorative layer, the first transparent layer, and the light reflective layer being formed in this order from an outer-layer side toward an inner side of the shaped article, wherein the manufacturing method for the shaped article employs multilayer lamination technique to form layers and comprises a layer forming process, and the layer forming process including: forming a part of the decorative layer, a part of the first transparent layer, and a part of the light reflective layer in this order from an end side toward a center side of each one of the layers

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims the prioritybenefit of U.S. patent application Ser. No. 15/116,513 filed on Aug. 4,2016, now pending, which is a 371 application of an international PCTapplication serial no. PCT/JP2015/053039, filed on Feb. 4, 2015, whichclaims the priority benefit of Japan application no. JP 2014-020776,filed on Feb. 5, 2014, Japan application no. JP 2014-020786, filed onFeb. 5, 2014, and Japan application no. JP 2014-020784, filed on Feb. 5,2014. The entirety of each of the above-mentioned patent applications ishereby incorporated by reference herein and made a part of thisspecification.

TECHNICAL FIELD

This disclosure relates to manufacturing method for a shaped article.

BACKGROUND ART

Examples of known techniques that may be employed to moldthree-dimensional objects include the sheet lamination method asdescribed in Patent Literature 1, as well as fuse deposition molding(FDM), inkjet method, inkjet binder method, stereolithography (SL), andselective laser sintering (SLS).

Among the known techniques is often employed a technique, patternlamination, wherein ultraviolet-curable resins are discharged from 3Dprinters to form multilayered objects. To produce a three-dimensionalobject, this method generates data of exterior and interior designs andstructures of a final product using a three-dimensional CAD, and slicesthe data using a computer to generate a multilayer laminate patterndata. Then, an ultraviolet-curable resin is discharged from a headaccording to the pattern data and stacked in layers.

Conventionally, three-dimensional objects thus molded may be decorated(with patterns and/or colors).

CITATION LIST Patent Literature

Patent Literature 1: JP 2003-71530 A (disclosed on Mar. 11, 2003)

SUMMARY Technical Problems

The inventors of this application found a problem with the known inkjet3D molding, which occurred when a molding ink and decorative inks(coloring inks of, for example, yellow, magenta, cyan, and black) weredischarged by inkjet printing technique. The problem is, once themolding ink and the decorative inks blend into one another at theirinterfaces, a shaped article may no longer be decorated as desired(failure to record characters and images in colors by way of subtractivecolor mixture).

Such intermixing of inks may be more apparent, particularly, in parts tobe decorated on a mold surface extending in a direction perpendicular tothe in-plane direction of layers. This is because relative movements ofan inkjet head and a shaped article along the in-plane direction oflayers may be prone to lower the positional accuracy in the in-planedirection of inks discharged from the inkjet head, consequently causingthe molding ink and the decorative inks to be intermixed.

In view of the issue, this disclosure is directed to providing a shapedarticle that may be decorated as desired, and a manufacturing method forsuch a shaped article.

Solutions to the Problems

To address the issue, a shaped article disclosed herein includes: alight reflective layer formed from an ink having light reflectiveness; adecorative layer; and a first transparent layer formed from atransparent ink, wherein the decorative layer, the first transparentlayer, and the light reflective layer are formed in this order from anouter-layer side toward an inner side of the shaped article.

This shaped article has the first transparent layer between thedecorative layer and the light reflective layer, preventing the lightreflective ink forming the light reflective layer from blending into anink forming the decorative layer. Supposing that the decorative layer isa colored layer formed from a colorant-containing ink, thecolorant-containing ink, if mixed with the light reflective ink formingthe light reflective layer, may lose its original colors, therebyfailing to produce an intended color tone. In this shaped article,however, even if the ink of the decorative layer is mixed into thetransparent ink of the first transparent layer, this does not deprivethe decorative layer ink of its original colors, producing no adverseimpact on decorative effects of the shaped article. The shaped article,therefore, may be successfully decorated as desired.

The shaped article disclosed herein according to an aspect is furthercharacterized in that the light reflective layer is formed from an inkcontaining a white pigment.

In the shaped article thus further characterized, the light reflectivelayer formed from the white pigment-containing ink may adequatelyreflect light entering through the decorative layer from the outer-layerside of the shaped article. As a result, the shaped article may befavorably decorated with colors by the subtractive color mixture.

In another aspect of this disclosure, the shaped article furtherincludes a second transparent layer formed from a transparent ink on theouter-layer side of the decorative layer.

The second transparent layer may serve to protect the decorative layerto prevent decolorization under friction and color fading by exposure toultraviolet. The second transparent layer may also contribute toelaborateness and high accuracy of the shaped article.

The shaped article disclosed herein according to yet another aspect isfurther characterized in that the decorative layer formed has its inkdensity filled by a transparent supplementary ink in a part of thedecorative layer in which decorative inks alone are insufficient to meeta predetermined ink density.

Using the decorative inks alone to form the decorative layer may lead toabundant ink supply in its parts to be decorated at higherconcentrations, while supplying less inks in its parts to be decoratedat lower concentrations. Such variability of the ink density indifferent parts of the decorative layer may generate irregularitiesand/or voids in the decorative layer. The irregularities and/or voidsmay provoke optical diffuse reflection and/or deflection, resulting inunattractive appearance of the decorative layer, or may incur failure toobtain any desired shape of the shaped article in the manufacturingprocess. On the other hand, the shaped article characterized asdescribed may eliminate the risk of such irregularities and/or voidsbecause the ink density of the decorative layer is filled by thetransparent supplementary ink. The shaped article, therefore, may besuccessfully decorated as desired and also shaped as desired.

The shaped article disclosed herein according to yet another aspect isfurther characterized in that the shaped article includes a plurality oflayers stacked on one another, wherein two or more of the plurality oflayers each include a part of the decorative layer, a part of the firsttransparent layer, and a part of the light reflective layer that areformed in this order from an end side toward a center side of each oneof the layers.

In yet another aspect of this disclosure, the shaped article furtherincludes a second transparent layer formed from a transparent ink on theouter-layer side of the decorative layer, wherein the two or more of theplurality of layers each include a part of the decorative layer betweena part of the first transparent layer and a part of the secondtransparent layer.

The shaped article disclosed herein according to yet another aspect isfurther characterized in having a region in which the layers are stackedon one another, the layers each including a part of the decorative layerbetween a part of the first transparent layer and a part of the secondtransparent layer. In this shaped article, in a portion of the regionwith no overlap between a part of the decorative layer in one of thelayers and a part of the decorative layer in another one of the layerson or below the one of the layers, there is an overlap between a part ofthe decorative layer in one of the layers and a part of the firsttransparent layer or a part of the second transparent layer in anotherone of the layers on or below the one of the layers.

Such an overlap in the vertical direction between the decorative layerand the transparent layer may suppress the possibility that the lightreflective layer is present on and below the decorative layer (layeroverlap ratio). By overlapping the decorative layer with the transparentlayer in the vertical direction, intermixing, if any, may occur betweenthe decorative layer and the transparent ink. Hence, the shaped articlemay be successfully decorated as desired.

A shaped article manufacturing method disclosed herein is amanufacturing method for a shaped article including a decorative layer,a first transparent layer, and a light reflective layer formed from anink having light reflectiveness, wherein the decorative layer, the firsttransparent layer, and the light reflective layer are formed in thisorder from an outer-layer side toward an inner side of the shapedarticle. This method employs the multilayer lamination technique to formlayers and includes a layer forming process including forming a part ofthe decorative layer, a part of the first transparent layer, and a partof the light reflective layer in this order from an end side toward acenter side of each one of the layers.

In the presence of the first transparent layer between the decorativelayer and the light reflective layer, the ink of the decorative layer,though possibly mixed with the transparent ink of the first transparentlayer during the manufacturing process, may be prevented from blendinginto the light reflective ink of the light reflective layer. Supposingthat the decorative layer is a colored layer formed from acolorant-containing ink, the colorant-containing ink, if mixed with thelight reflective ink forming the light reflective layer, may lose itsoriginal colors, thereby failing to produce an intended color tone. Inthis shaped article, however, even if the ink of the decorative layer ismixed into the transparent ink of the first transparent layer, this doesnot deprive the decorative layer ink of its original colors, producingno adverse impact on decorative effects of the shaped article. Theshaped article, therefore, may be successfully decorated as desired.

The shaped article manufacturing method is further characterized in thatthe layer forming process includes forming a second transparent layerusing a transparent ink on the outer-layer side of the decorative layerby forming a part of the second transparent layer at a position nearerto the end side than a part of the decorative layer in each of thelayers.

The second transparent layer may serve to protect the decorative layerto prevent decolorization under friction and color fading by exposure toultraviolet. The second transparent layer may also contribute toelaborateness and high accuracy of the shaped article.

Specifically, a part of the second transparent layer is formed before apart of the decorative layer is formed in each of the layers. This mayallow the formed part of the second transparent layer to serve as theouter moat for a part of the decorative layer to be later formed,preventing part of the decorative layer from spreading unintendedly.

At the time of forming the upper decorative layer of two layersvertically formed, the second transparent layer already formed as itsunderlayer may allow a larger formation area to be secured for thedecorative layer. Such an increase of the decorative layer formationarea may prevent the risk that the ink applied to form the upperdecorative layer runs off an edge of its underlayer and drops downward.Hence, the shaped article may be successfully manufactured as desired.

The shaped article manufacturing method disclosed herein is furthercharacterized in that the layer forming process includes steps of:forming a part of the decorative layer; forming a part of the firsttransparent layer using a transparent ink; forming a part of the lightreflective layer using an ink having light reflectivity; and forming apart of the second transparent layer using a transparent ink, whereinthe step of forming a part of the decorative layer is performedsubsequent to the step of forming a part of the first transparent layerand the step of forming a part of the second transparent layer to form apart of the decorative layer between the parts of the first transparentlayer and the second transparent layer.

Thus, a part of the first transparent layer and a part of the secondtransparent layer are formed before a part of the decorative layer isformed as described earlier. This may allow the parts of the first andsecond transparent layers to serve as the outer moat for a part of thedecorative layer to be later formed, preventing the part of thedecorative layer from spreading unintendedly. The shaped article,therefore, may be successfully manufactured as desired.

The shaped article manufacturing method disclosed herein furtherincludes providing, in a portion of the region with no overlap between apart of the decorative layer in one of the layers and a part of thedecorative layer in another one of the layers on or below the one of thelayers, an overlap between a part of the decorative layer in one of thelayers and a part of the first transparent layer or a part of the secondtransparent layer in another one of the layers on or below the one ofthe layers.

The decorative layer may be interposed between the transparent layers inthe layer-stacked direction as well. This may avoid an overlap betweenthe parts of the decorative layer in the upper and lower layers. Theshaped article thus formed may not exhibit undesirable variability incolor tone when viewed in a certain direction or when viewed in anotherdirection inclined from the direction.

The shaped article manufacturing method disclosed herein is furthercharacterized in forming a part of the decorative layer by filling theink density of the decorative layer using a transparent supplementaryink in a part of the decorative layer in which decorative inks alone areinsufficient to meet a predetermined ink density.

By having the ink density of the decorative layer partly filled by thesupplementary ink, it may be avoided that the decorative layer partlyhas undesirable irregularities and/or voids. Using the decorative inksalone to form the decorative layer may lead to abundant ink supply inits parts to be decorated at higher concentrations, while supplying lessinks in its parts to be decorated at lower concentrations. Suchvariability of the ink density in different parts of the decorativelayer may generate irregularities and/or voids in the decorative layer.The irregularities and/or voids may provoke optical diffuse reflectionand/or deflection, resulting in unattractive appearance of thedecorative layer, or may incur failure to obtain any desired shape ofthe shaped article in the manufacturing process. On the other hand, theshaped article manufacturing method characterized as described mayeliminate the risk of such irregularities and/or voids because the inkdensity of the decorative layer is filled by the transparentsupplementary ink. The shaped article, therefore, may be successfullydecorated as desired and also shaped as desired.

Effect of the Disclosure

This disclosure may provide a shaped article exhibiting a desired colortone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an outer shape of a shaped articledisclosed herein according to an embodiment.

FIG. 2 is a cross-sectional view of the shaped article of FIG. 1 takenalong a cutting-plane line A-A′.

FIG. 3 is a schematic drawing of inkjet heads used in manufacturing ofthe shaped article of FIG. 1, illustrating a surface where nozzle holesare located.

FIG. 4 shows drawings of manufacturing steps for the shaped article ofFIG. 1.

FIG. 5 is an upper view of the shaped article of FIG. 1 currently beingmanufactured.

FIG. 6 is a partial cross-sectional view of the shaped article of FIG. 1illustrated to describe its advantages.

FIG. 7 is a partial cross-sectional view of a shaped article forcomparison.

FIG. 8 shows perspective views each illustrating a shaped articledisclosed herein according to a modified example.

FIG. 9 is a cross-sectional view of a shaped article disclosed hereinaccording to another embodiment.

FIG. 10 is a schematic drawing of inkjet heads used in manufacturing ofthe shaped article of FIG. 9, illustrating a surface where nozzle holesare located.

FIG. 11 shows drawings of manufacturing steps for the shaped article ofFIG. 9.

FIG. 12 is a schematic drawing of another example of inkjet heads usedin manufacturing of the shaped article disclosed herein.

FIG. 13 is a schematic drawing of yet another example of inkjet headsused in manufacturing of the shaped article disclosed herein.

FIG. 14 is a schematic drawing of yet another example of inkjet headsused in manufacturing of the shaped article disclosed herein.

DESCRIPTION OF EMBODIMENTS First Embodiment

An embodiment of a shaped article and a shaped article manufacturingmethod disclosed herein is hereinafter described referring to FIG. 1 toFIG. 8. The shaped article disclosed herein has a three-dimensionalstructure constructed of a laminate of layers (formed by multilayerlamination technique). In the embodiment hereinafter described, inkjetprinting technique is employed to manufacture the shaped article. Thisis, however, just an option presented in this disclosure. Thisdisclosure may be applicable to any kinds of manufacturing methods thatcan obtain a shaped article by leveraging the multilayer laminationtechnique and decorate its surface (recording of characters and imagesin colors).

[1] Structure of Shaped Article

FIG. 1 is a perspective view of an outer shape of a shaped article 50according to an embodiment. The shaped article 50 according to thisembodiment has a substantially cylindrical shape with a curved sidesurface bulging outward. The shaped article disclosed herein and theshaped article manufactured by the manufacturing method disclosed hereinmay not be limited to the shape illustrated in FIG. 1. There are manyother examples of the shape, including a hexahedral shape describedlater, a spherical shape, a hollow structure, a ring-like shape, and ahorseshoe-like shape.

The shaped article 50 according to this embodiment includes a secondtransparent layer, a colored layer (decorative layer) formed fromcolorant-containing inks (decorative ink), a first transparent layerformed from a transparent ink, and a light reflective layer formed froman ink having light reflectiveness, wherein these layers are formed inthe mentioned order from an outer-layer side (outer peripheral side)toward an inner side (center) of the shaped article 50. This is adistinctive technical feature of this disclosure. FIG. 1 is a drawing ofthe shaped article 50. In this drawing, a second transparent layer 4formed from a transparent ink, which is the outermost layer, can be seenon the curved side surface of the shaped article 50.

FIG. 2 is a cross-sectional view of the illustration of FIG. 1 takenalong a cutting-plane line A-A′. The cross-sectional view of the shapedarticle 50 illustrated in FIG. 2 is taken at a central position of theshaped article 50 along the X-Z plane of the XYZ coordinate systemillustrated in FIG. 1.

The embodiment of FIG. 2 presents an example of the shaped article 50having a three-dimensional structure formed by stacking 21 layers 50 aon one another in the Z direction. It should be understood that theshaped article 50 may include less than or more than 21 layers.

[2] Structures of Layers

FIG. 5 is a drawing of the X-Y plane of a layer 50 a in the vicinity ofa mid-stage of the shaped article 50. The layers 50 a each include apart 54 of the second transparent layer, a part 53 of the colored layer,a part 52 of the first transparent layer, and a part 51 of the lightreflective layer. These layers are formed in the mentioned order from anouter peripheral side toward a center side of the shaped article. If theshaped article 50 according to this embodiment is stated another way,the light reflective layer 1, which is the body of the shaped article,is coated with the first transparent layer 2, colored layer 3, andsecond transparent layer 4 in the mentioned order toward the outer-layerside (outer peripheral side). Each one of the layers 50 a has athickness in the Z direction (vertical direction in the drawing) between5 μm and 50 μm. This is an adequate range of thickness values formulticolor formation of the colored layer 3 using the subtractive colormixture. For example, a preferable range of thickness values is 10 μm to25 μm when layers are formed from inks of ultraviolet curing type byinkjet printing technique.

In this embodiment, the light reflective layer 1 is the body of theshaped article; however, the light reflective layer may or may notconstitute the body of the shaped article. Specifically, the shapedarticle may have, at its center, a body or a cavity apart from the lightreflective layer, wherein the light reflective layer, first transparentlayer, colored layer, and second transparent layer are formed in thementioned order from the body (may or may not have light reflectiveness)toward the outer-layer side (outer peripheral side). Alternatively, acore (may or may not have light reflectiveness) and the light reflectivelayer 1 formed on a surface of the core may be collectively regarded asthe body of the shaped article.

By stacking the layers 50 a in the Z direction as illustrated in FIG. 2,the parts 54 of the second transparent layer in the respective layers 50a are substantially continuous in a direction along the outermostsurface of the shaped article 50, forming the second transparent layer4. The parts 53 of the colored layer in the respective layers 50 a aresubstantially continuous in the direction along the outermost surface ofthe shaped article 50, forming the colored layer 3. The parts 52 of thefirst transparent layer in the respective layers 50 a are substantiallycontinuous in the direction along the outermost surface of the shapedarticle 50, forming the first transparent layer 2. The parts 51 of thelight reflective layer in the respective layers 50 a are substantiallycontinuous in the direction along the outermost surface of the shapedarticle 50, forming the light reflective layer 1.

Looking at, in any of the X, Y, and Z directions, the outer surface ofthe shaped article 50 including the second transparent layer, coloredlayer, first transparent layer, and light reflective layer arranged inthe mentioned order, a color tone produced by the subtractive colormixture may be visually recognized.

The parts 52 of the first transparent layer may preferably have adimension in the direction of X-Y plane slightly greater than the part53 of the colored layer vertically in contact with the parts 52. Thismay more reliably prevent intermixing of the inks forming the coloredlayer 3 and the light reflective layer 1.

The parts 54 of the second transparent layer may preferably have adimension in the direction of X-Y plane slightly greater than the parts53 of the colored layer vertically in contact with the parts 54 of thesecond transparent layer. This may provide for better protection of thecolored layer 3.

The width of the shaped article 50 along the Z direction (hereinaftermay be referred to as thickness or height in the Z direction) is notparticularly limited. The thickness (height) of the layer 50 a in the Zdirection may be optionally decided depending on the number of layers.As described later, this embodiment constructs the multilayeredstructure using the inkjet printing technique. Therefore, any feasiblevalues in the technique should be contemplated for the thickness of thelayer 50 a in the Z direction. When inks of ultraviolet curing type areapplied by inkjet printing technique to form the layers (describedlater), the layer 50 a may have a thickness ranging from 5 μm to 20 μmdepending on the sizes of ink droplets. As for a large-sized shapedarticle for which a high resolution is not particularly required, plurallayers may be formed based on the same data simply by increasing thesizes of ink droplets. In such a case, a smaller data volume and ahigher molding rate may be anticipated.

[3] Structure of Light Reflective Layer 1 (Parts 51 of Light ReflectiveLayer)

The light reflective layer 1 (parts 51 of the light reflective layer) isa layer formed from a light reflective ink. This layer, therefore, haslight reflectiveness that allows rays of light in the whole visiblelight region to be reflected on at least the surface of the lightreflective layer 1 in contact with the colored layer.

Specific examples of ink of the light reflective layer 1 (parts 51 ofthe light reflective layer) may include metallic powder-containing inksand white pigment-containing inks. The light reflective layer 1 maypreferably be formed from a white ink. The light reflective layer 1formed from a white ink may adequately reflect rays of light enteringfrom the outer-layer side of the shaped article, allowing the shapedarticle to be colored by the subtractive color mixture.

In this embodiment, the light reflective layer 1 constitutes the body ofthe shaped article. In case the light reflective layer 1 is formed onthe surface of the body of any shaped article for which lightreflectiveness is not required, the thickness of the light reflectivelayer 1, i.e., the width of the part 51 of the light reflective layerfrom the outer peripheral side to the center side, as illustrated inFIG. 2, may be between 5 μm and 20 μm at the least. The width in thisdisclosure may include but is not limited to the range of values.

[4] Structure of First Transparent Layer 2 (Parts 52 of FirstTransparent Layer)

The first transparent layer 2 (parts 52 of the first transparent layer)is formed from a transparent ink.

The transparent ink may refer to an ink capable of forming a transparentlayer having light transmittance greater than or equal to 50% per unitthickness. The light transmittance less than 50% per unit thickness ofthe transparent layer may unintendedly block the transmission of light.This may be a drawback that fails to exhibit a desired color tone of theshaped article by way of the subtractive color mixture. Preferably isused an ink having light transmittance greater than or equal to 80% perunit thickness of the transparent layer. Further, an ink having lighttransmittance greater than or equal to 90% per unit thickness of thetransparent layer is particularly preferable.

By interposing the first transparent layer 2 (part 52 of the firsttransparent layer) between the light reflective layer 1 (part 51 of thelight reflective layer) and the colored layer 3 (part 53 of the coloredlayer), intermixing of the coloring inks of the colored layer 3 and theink of the light reflective layer 1 may be avoidable. Even if thecoloring inks applied to form the colored layer are mixed with thetransparent ink of the first transparent layer, intermixing of theseinks may not adversely affect colors of the colored layer or cause anyundesirable change to the color tone. Therefore, the resulting shapedarticle exhibits a desired color tone (decorated as desired) expressedby the colored layer 3.

The width of the part 52 of the first transparent layer from the outerperipheral side to the center side (hereinafter, referred to as thethickness of the first transparent layer) is between 5 μm and 20 μm atthe least in a decorated portion on a surface perpendicular to thelayer-stacked direction. The width in this disclosure may include but isnot limited to the range of values.

[5] Structure of Colored Layer 3 (Part 53 of Colored Layer)

The colored layer 3 (part 53 of the colored layer) is formed from acolorant-containing coloring ink.

Examples of the colorant-containing inks (hereinafter may be referred toas coloring ink) may include but are not limited to yellow (Y), magenta(M), cyan (C), black (K), and pale color inks. Further, red (R), green(G), blue (B), and orange (Or) color inks may be additionally used.Other usable inks may include metallic, pearl, and phosphor inks. One ormore than one of these coloring inks may preferably be used to express adesired color tone.

The amounts of the coloring inks to form the colored layer 3 (parts 53of the colored layer) may be variable depending on a desired (desirablyexpressed) color tone. In case the coloring inks alone are used toexpress a bright color tone at a relatively low concentration, the inkdensity of the colored layer 3 may fail to meet a predetermined inkdensity. This may generate irregularities in the Z direction and/orink-less dented parts at positions along the X-Y direction. In any case,the shaped article formed by the multilayer lamination technique, asdescribed in this embodiment, may consequently have an irregular,unattractive shape, which is desirably avoided. In case onecross-sectional surface of the colored layer 3 has the ink density oftwo lateral and two vertical ink droplets; four ink droplets in total,formed by the error diffusion method on a vertical mold surface near themid position of the multilayered structure illustrated in FIG. 2, thecoloring inks each form four ink droplets at the most (largestconcentration) and no ink droplet at the least (zero concentration,meaning colorless). The number of ink droplets being zero may leave anunfilled space as large as four ink droplets, significantly degradingthe shaped article in view of its shape and color tone.

This embodiment, therefore, fills the ink density of the colored layer 3(part 53 of the colored layer) using a supplementary ink in parts of thecolored layer 3 (part 53 of the colored layer) in which the coloringinks alone are insufficient to meet a predetermined ink density.Specifically, the colored layer 3 (parts 53 of the colored layer) isformed at a constant total density (number of ink droplets) of thecoloring inks and the supplementary ink. This may successfully preventthe formation of dented parts, allowing the shaped article 50 to beelaborately shaped.

The amounts of the coloring inks to be discharged and their landingpositions are known beforehand, based on which the amount and position(landing position) of the supplementary ink to be additionallydischarged may be suitably determined. The amount and position may bedecided by an inkjet head device 10 or by a controller not illustratedin the drawings.

Having the ink density filled by the supplementary ink may allow asurface formed by the colored layer 3 to be flattened, impartingglossiness to the surface.

The supplementary ink may be any ink unless it adversely affects thecolor tone to be expressed by the colored layer 3 (parts 53 of thecolored layer). An example of the supplementary ink may be thetransparent ink used to form the first transparent layer 2 (parts 52 ofthe first transparent layer) and the second transparent layer 4 (parts54 of the first transparent layer).

The thickness of the colored layer 3, i.e., the width of the part 53 ofthe colored layer from the outer peripheral side to the center sideillustrated in FIG. 2 (hereinafter, referred to as the thickness of thecolored layer 3) may be between 5 μm and 20 μm.

The colored layer 3 described in this embodiment is just an option andmay be any decorative layer.

[6] Structure of Second Transparent Layer 4 (Parts 54 of SecondTransparent Layer)

The second transparent layer 4 (parts 54 of the second transparentlayer) is formed from the same transparent ink as that of the firsttransparent layer 2 (parts 52 of the first transparent layer). The sametransparent ink or different transparent inks may be used to form thesecond transparent layer 4 and the first transparent layer 2.

The thickness of the second transparent layer 4, i.e., the width of thepart 54 of the second transparent layer from the outer peripheral sideto the center side illustrated in FIG. 2 (hereinafter, referred to asthe thickness of the second transparent layer 4) may be between 10 μmand 100 μm.

The second transparent layer 4 functions as a protective layer for thecolored layer 3. In this disclosure that employs the multilayerlamination technique (this embodiment), the second transparent layer 4may also advantageously contribute to elaborateness of the shapedarticle.

Supposing that the colored layer 3 is the outermost layer of the shapedarticle 50, i.e., the parts 53 of the colored layer are located at thefarthest ends of the respective layers 50 a illustrated in FIG. 2, thecolored layer 3 (parts 53 of the colored layer) formed may not be asaccurate as expected. On the other hand, the shaped article 50 whoseoutermost layer is the second transparent layer 4 (parts 54 of thesecond transparent layer), as described in this embodiment, may ensurethe accuracy of the colored layer 3 (parts 53 of the colored layer).Thus, the second transparent layer 4 (parts 54 of the second transparentlayer) may greatly contribute to a desired color tone.

Another disadvantage in case the colored layer 3 is the outermost layerof the shaped article 50 is that the exposed colored layer 3 may beprone to decolorization under friction and color fading by exposure toultraviolet. However, as described in this embodiment, the shapedarticle 50 whose outermost layer is the second transparent layer 4(parts 54 of the second transparent layer) may prevent such unfavorableevents as decolorization and color fading.

[7] Manufacturing Method for Shaped Article

A manufacturing method for the shaped article 50 according to thisembodiment is hereinafter described. FIG. 3 is a drawing of the lowersurface of the inkjet head device 10 used in the manufacturing method.FIG. 4 shows schematic drawings of ongoing steps of manufacturing theshaped article 50 according to this embodiment.

The inkjet head device 10 has, on its lower surface, roughly threeinkjet heads 11H to 13H. As illustrated in FIG. 3, the first inkjet head11H, second inkjet head 12H, and third inkjet head 13H are displacedfrom one another in the X direction. As illustrated in FIG. 3, the firstinkjet head 11H, second inkjet head 12H, and third inkjet head 13H arealso displaced from one another in the Y direction. Thus, the inkjetheads 11H to 13H are positioned in, generally called, staggeredarrangement.

The first inkjet head 11H has a cyan ink nozzle 10 (C) for discharging acyan ink, a magenta ink nozzle 10 (M) for discharging a magenta ink, ayellow ink nozzle 10 (Y) for discharging a yellow ink, and a black inknozzle 10 (K) for discharging a black ink. The number and the order ofarrangement of the nozzles 10 (C), 10 (M), 10 (Y), and 10 (K) are notlimited to the example illustrated in FIG. 3. All of the inks dischargedthrough these nozzles are coloring inks used to form the colored layer 3(parts 53 of the colored layer) illustrated in FIG. 2.

The second inkjet head 12H has a white ink nozzle 10 (W) for discharginga white ink (W). The white ink (W) is an ink used to form the lightreflective layer 1 (parts 51 of the light reflective layer) illustratedin FIG. 2.

The third inkjet head 13H has a transparent ink nozzle 10 (CL) fordischarging a transparent ink (CL). The transparent ink (CL) is an inkused to form the first transparent layer 2 (parts 52 of the firsttransparent layer) and the second transparent layer 4 (parts 54 of thesecond transparent layer) illustrated in FIG. 2.

The inkjet head device 10 is located so as to have its lower surfaceillustrated in FIG. 3 face the layer 50 a currently being formed. Theinkjet head device 10 is configured to reciprocate in the X directionand discharge the inks while moving in the direction. The inkjet headdevice 10 is moved in a predetermined direction in an XYZ coordinatesystem, or a table with the layers 50 a placed thereon (FIG. 4 shows alayer formation surface B of the table) is moved in a predetermineddirection in the XYZ coordinate system to change relative positions ofthe inkjet head device 10 and the layer 50 a currently being formed.Which one of them should be moved may be optionally decided.

Each of the inks is an ink of ultraviolet curing type that needs to beirradiated with ultraviolet light after being discharged. An ultravioletirradiator may be mounted in the inkjet head device 10 or may beinstalled as a separate device. The inks are cured by being irradiatedwith ultraviolet light to form the layers 50 a illustrated in FIG. 2.

The manufacturing process for the shaped article 50 using the inkjethead device 10 is hereinafter described referring to FIG. 4.

To start with, a first one of the layers 50 a (first layer 50 a (1)) isformed on the layer formation surface B of the table.

In the step of forming (manufacturing) the first layer 50 a (1), byusing the inkjet printing technique, the respective inks are dischargedfrom the inkjet head device 10 at predetermined timings to form a partof the second transparent layer, a part of the colored layer, a part ofthe first transparent layer, and a part of the light reflective layer inthe mentioned order from the end side toward the center side of thefirst layer 50 a.

The steps of forming (manufacturing) the first layer 50 a (1) aredescribed in further detail referring to (a)˜(c) of FIG. 4.

In step S1 illustrated in (a) of FIG. 4, the part 54 of the secondtransparent layer is formed from the transparent ink, and the part 52 ofthe first transparent layer is formed from the transparent ink. In thisstep, the inkjet head device 10 is moved in a positive direction alongthe X axis, and the transparent ink is discharged at a predeterminedtiming through the transparent ink nozzle 10 (CL) illustrated in FIG. 3.The discharged ink lands on a position at which the part 54 of thesecond transparent layer should be formed and a position at which thepart 52 of the first transparent layer should be formed. Then, thedischarged ink pooled at the respective positions is irradiated withultraviolet light to be cured. As a result, the part 52 of the firsttransparent layer and the part 54 of the second transparent layer areformed as illustrated in (a) of FIG. 4.

In step S2 illustrated in (b) of FIG. 4, the inkjet head device 10 ismoved in a negative direction along the X axis, and the white ink (W),which is the light reflective ink, is discharged at a predeterminedtiming through the white ink nozzle 10 (W). Then, the discharged inkpooled there is irradiated with ultraviolet light to be cured. As aresult, the part 51 of the light reflective layer is formed asillustrated in (b) of FIG. 4.

In step S3 illustrated in (c) of FIG. 4, the inkjet head device 10 ismoved in the positive direction along the X axis, and the colored layerforming inks including the coloring inks and the supplementary ink aredischarged at a predetermined timing so that the total amount of theseinks discharged is constant, and then irradiated with ultraviolet light.The predetermined timing refers to a timing at which the nozzles of thefirst inkjet head 11H are located at positions at which the coloredlayer forming inks are dischargeable in a region between the part 52 ofthe first transparent layer and the part 54 of the second transparentlayer formed in step S1. The ink droplets in a predetermined amount aredischarged by inkjet printing technique at this timing to form a pool ofink. Then, the pooled ink is irradiated with ultraviolet light to becured. This forms the part 53 of the colored layer exhibiting a desiredcolor tone between the part 52 of the first transparent layer and thepart 54 of the second transparent layer as illustrated in FIG. 4.

As a result of steps S1 to S3, the formation of the first layer 50 a (1)is completed. The first layer 50 a (1) has the same structure asillustrated in the upper view of the layer 50 a in FIG. 5. Optionally,step 1 and step 2 may be performed in the reversed order. Likewise, stepS2 and step S3 may be performed in the reversed order.

After the first layer 50 a (1) is formed, a new layer 50 a (second layer50 a (2)) is formed on the first layer 50 a (1) (laminate of layers).

In the shaped article 50 according to this embodiment, the layers 50 astacked on one another are progressively increased in size (area) fromthe bottom toward the mid stage of the multilayered body as illustratedin FIG. 2. In the shaped article 50 manufactured in such a shape thatincreases in size along the layer-stacked direction when viewed in crosssection, the end of one layer 50 a is sticking out sideways further thanthe end of another layer 50 a already formed below the one layer 50 a.To form the layers 50 a thus characterized, support material layers maypreferably be formed.

In FIG. 4, (d) is a drawing of the step of forming the second layer 50 a(2). Referring to this drawing, a part 53 (2) of the colored layer inthe second layer 50 a (2) is formed so as to overlap a part 54 (1) ofthe second transparent layer in the first layer 50 a (1). Since thesecond layer 50 a (2) is greater in size (area) along the X-Y plane thanthe first layer 50 a (1), the part 54 (2) of the second transparentlayer forming the end of the second layer 50 a (2) is sticking outsideways further than the part 54 (1) of the second transparent layerforming the end of the first layer 50 a (1). Because of this structure,the ink to be deposited on a part of the layer 50 a (2) where thestick-out part should be formed possibly runs off this part and dropsdownward. To avoid that, a support material 60 is formed on the outerside (on the lateral side) than the part 54 (1) of the secondtransparent layer in the first layer 50 a (1).

The support material 60 may preferably be formed from any ink that canbe discharged by inkjet printing technique. The support material 60should preferably have enough strength not to collapse under the weightof another layer formed thereon. The support material 60 per se will notbe left in the finalized shaped article 50. The ink forming the supportmaterial 60, therefore, should preferably be selected from inks that canbe stripped off afterwards. The ink of the support material 60 maypreferably be curable by ultraviolet light (to a degree of cure at whichthe ink is stripped off in subsequent steps), or may be a water-solubleink that can be dissolved in water and removed in subsequent steps.

The steps of forming the layers 50 a are repeatedly performed in the Xand Y directions as many times as required to form one layer, and thenrepeatedly performed again in the Z direction. As a result, the shapedarticle 50 illustrated in FIG. 2 is finally obtained. During the stepsof forming one layer, the known interlace scan conventionally employedto form two-dimensional images may preferably be performed to obtain ashaped article with less unevenness in shape and favorably decorated.

The shaped article manufacturing method according to this embodiment isfurther characterized in that the layer forming process includes stepsof: forming the part 54 of the second transparent layer using thetransparent ink; forming the part 53 of the colored layer using thecoloring inks; forming the part 52 of the first transparent layer usingthe transparent ink; and forming the part 51 of the light reflectivelayer using the light reflective ink, wherein the step of forming thepart 53 of the colored layer is performed subsequent to the step offorming the part 52 of the first transparent layer and the step offorming the part 54 of the second transparent layer to form the part 53of the colored layer between the part 52 of the first transparent layerand the part 54 of the second transparent layer. When the part 53 of thecolored layer is formed, the part 54 of the second transparent layer mayserve as the outer moat of the pooled inks to form the colored layer.This may prevent the ink of the colored layer from spreadingunintendedly, ensuring a high accuracy of the part 53 of the coloredlayer.

Further benefits delivered by forming the part 54 of the secondtransparent layer are described referring to FIG. 6 and FIG. 7. FIG. 6is a drawing of a part of the shaped article 50 according to thisembodiment, which is the part of (d) of FIG. 4 from which the supportmaterial has been removed. FIG. 7 is a cross-sectional view of a shapedarticle for comparison. The shaped article for comparison is formed bythe multilayer lamination technique similarly to the shaped article 50according to this embodiment. Unlike the shaped article 50, however,this shaped article lacks parts corresponding to the part 52 of thefirst transparent layer and the part 54 of the second transparent layer.In this shaped article for comparison, therefore, the light reflectivelayer is directly coated with the colored layer. Provided that the upperlayer is larger in size (area) along the X-Y plane than the lower layerin the shaped article for comparison, problems with this shaped articleare described.

In the shaped article for comparison illustrated in FIG. 7, the end ofthe upper layer includes a colored layer 152 (2). The colored layer 152(2) is sticking out further than a colored layer 152 (1) formed on theend of the lower layer. This shaped article, therefore, involves therisk that the inks for the colored layer discharged to form thestick-out part run off a coloring position and drop downward.

The colored layer is the deciding factor for the color tone of theshaped article. Therefore, thus losing the inks of the colored layer maycause an intended color tone of the shaped article to change.

On the other hand, the shaped article 50 according to this embodimentillustrated in FIG. 6 has the parts 54 of the second transparent layerat the ends of the layers 50 a. The ink applied to form the parts 54 ofthe second transparent layer, even if it falls downward in FIG. 6, maynot adversely affect a color tone desirably expressed because thecolored layer is the deciding factor for the color tone. This embodimentmay thus successfully manufacture the shaped article 50 that excels inreliability and exhibits a desired color tone.

There are other benefits as well. One of them is, forming the part 54 ofthe second transparent layer in the first layer 50 a (1) allow a largerformation area (formation allowable region) to be secured for thecolored layer of the second layer 50 a (2). This may help to mitigate ademanded degree of manufacturing accuracy to some extent, conducing toan improved manufacturing efficiency.

The ability to secure a larger formation area is advantageouslyeffective even if the part 54 of the second transparent layer is formedsubsequent to the part 53 of the colored layer. This disclosure,therefore, further includes forming the part 54 of the secondtransparent layer subsequent to the part 53 of the colored layer.

In the shaped article 50 according to this embodiment, the surface ofthe colored layer 3 is coated with the second transparent layer 4. Thesecond transparent layer 4 thus serves as the protective layer of thecolored layer 3.

FIG. 4 illustrates an example in which the upper layer is greater insize (area) along the X-Y plane than the lower layer. This examplerefers to the lower half of the shaped article 50 of FIG. 1 split in twohalves.

The manufacturing method described so far is basically applicable to theupper-half structure of the shaped article 50 of FIG. 1 split in twohalves. As for the upper half of the shaped article 50, as illustratedin FIG. 2, the upper colored layer is nearer to the center side of thelayer 50 a than the lower colored layer, and the parts 53 of the uppercolored layer overlap the parts 52 of the lower first transparent layer.Further, the parts 54 of the upper second transparent layer overlap theparts 53 of the lower colored layer.

In the upper half of the shaped article 50, as illustrated in FIG. 2,the lower layers are greater in size (area) along the X-Y plane than theupper layers formed thereon. In this upper-half structure, the inkapplied to form the colored layer in the upper layers is very unlikelyto drop downward. No support material may be necessary at the time ofmanufacturing the upper-half structure.

In the shaped article of FIG. 2 according to this embodiment, the bottomlayer and layers nearby, and the top layer and layers nearby include: alayer solely having the part 52 of the first transparent layer, part 53of the colored layer, and part 54 of the second transparent layer; alayer solely having the part 53 of the colored layer and the part 54 ofthe second transparent layer; and a layer solely having the part 54 ofthe second transparent layer. This multilayered structure may effectuatea shaped article whose entire surface is covered with the secondtransparent layer 4, colored layer 3, and first transparent layer 2.This disclosure, however, is not limited to such a multilayeredstructure. For example, the top and bottom surfaces of the shapedarticle may include none of the second transparent layer, colored layer,or first transparent layer, as in the multilayered structure of FIG. 9described later.

[8] Modified Example First Modified Example

The shaped article 50 according to this embodiment includes the firsttransparent layer 2, colored layer 3, and second transparent layer 4that are formed along the surface of the light reflective layer 1.However, this disclosure may include but is not limited to such astructure, and may optionally have a shaped article illustrated in FIG.8.

In the shaped articles illustrated in (a)˜(d) of FIG. 8, the secondtransparent layer 4 may have a shape described below instead of theshape along the surface of the light reflective layer 1. Because theparts 54 of the second transparent layer constitute the ends of thelayers 50 a (FIG. 2), the second transparent layer 4 may be formed in anadequate shape that contains therein the shaped article (structuredescribed in the earlier embodiment including the colored layer 3, firsttransparent layer, and light reflective layer), as illustrated in(a)˜(d) of FIG. 8.

Containing the shaped article in the shape formed by the secondtransparent layer 4, as described in this first modified example, may beuseful for any shaped articles that are mechanically fragile. Forexample, this modified example may be effectively applicable when, forexample, molding insects' legs and wings, and stems and petals offlowering plants. When molding organisms and plants in the form ofdecorative ornaments or specimens, they can be scanned alive by athree-dimensional scanner and released again into the nature when themolding is over. A further benefit may be eco-friendliness because nosupport material is necessary, producing no waste material.

In the shaped article illustrated in (a) of FIG. 8, the secondtransparent layer 4 has a hexahedral shape that contains a sphericalbody including the colored layer 3, first transparent layer, and lightreflective layer. The structure illustrated in (a) of FIG. 8 may beobtained by a manufacturing method similar to the method of FIG. 4.

In FIG. 8, (b) illustrates a shaped article 50 of frame-mounted type,wherein a figure including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4. This is a free-standing shaped article 50 supported by the secondtransparent layer 4. This shaped article 50 of frame-mounted type may bemanufactured (fabricated) by the manufacturing method described in theearlier embodiment.

In FIG. 8, (c) illustrates a shaped article 50 for use as a strap,wherein a figure including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4, and a hole 70 is formed in a part of the second transparent layer 4.This may be used as a strap or a key holder attachable to, for example,a mobile telephone. The hole 70 of the second transparent layer 4 may beformed at the same time when the outer shape is formed by the secondtransparent layer 4. By punching a hole in the second transparent layer4, the figure including the colored layer 3, first transparent layer,and light reflective layer can avoid being damaged with a hole.

In the shaped article 50 illustrated in (d) of FIG. 8, the upper-half ofa figure's body including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4. This article 50 has, on the surface or inside of the secondtransparent layer 4, a three-dimensional image 71 decorated with a markor a frame or painted in a pale color. This shaped article 50 furtherhas, on the surface or inside of the second transparent layer 4, aletter/character area 72 with letters and/or characters representingdate, name, or place. The decorated three-dimensional image 71 and theletter/character area 72 may be formed at the same time when the outershape is formed by the second transparent layer 4. Instead of thedecorated three-dimensional image 71 and the letter/character area 72,other additional information may be displayed on the surface or insideof the second transparent layer 4.

In (b)˜(d) of FIG. 8, one figure is contained in the second transparentlayer 4; however, the number of figures containable in the secondtransparent layer 4 may be other than one.

In case the shaped article according to this embodiment has a ring-likeshape, the colored layer may be formed near an inner peripheral end ofthe ring shape as well as an outer peripheral end thereof. Inconclusion, the colored layer may be formed on the surface of the shapedarticle, and the second transparent layer may be further formed thereon.

Instead of forming the second transparent layer 4 in any desired shapeas described in this modified example, the second transparent layer 4may be formed in a shape suitable for the surface of the lightreflective layer 1 similarly to the earlier embodiment. In that case,the obtained shaped article may be sealed in an optionally-shaped resin.

Second Modified Example

The shaped article 50 according to this embodiment has the secondtransparent layer 4 on its outermost side. This disclosure may achieveits goal in so far as the first transparent layer is interposed betweenthe colored layer and the light reflective layer. This disclosure,therefore, may include, as an embodiment, a shaped article 50′illustrated in cross section in FIG. 9. A second modified example ishereinafter described referring to FIG. 9 to FIG. 11. FIG. 9 is across-sectional view of the shaped article 50′ according to the secondmodified example, illustrated similarly to FIG. 2. FIG. 10 is aschematic drawing of the lower surface of an inkjet head deviceaccording to the second modified example used in manufacturing of theshaped article 50′. FIG. 11 shows drawings of manufacturing steps forthe shaped article 50′ according to the second modified example.

A difference between the shaped article 50′ according to the secondmodified example and the shaped article 50 according to the earlierembodiment is that the shaped article 50′ according to the secondmodified example has the colored layer 3 as its outermost layer, unlikethe shaped article 50 whose outermost layer is the second transparentlayer 4.

Referring to FIG. 9, layers 50′a constituting the shaped article 50′according to the second modified example include no part 54 of thesecond transparent layer, unlike the layers 50 a according to theearlier embodiment (FIG. 2) having these parts 54 at their ends.

In the layers 50′a of the shaped article 50′ illustrated in FIG. 9, theparts 52 of the first transparent layer are interposed between the parts53 of the colored layer and the parts 51 of the light reflective layer.This may prevent the coloring inks applied to form the parts 53 of thecolored layer from blending into the ink of the parts 51 of the lightreflective layer. Even if the coloring inks of the part 53 of thecolored layer are mixed with the transparent ink of the part 52 of thefirst transparent layer, intermixing of these inks may cause noundesirable change to the color tone of the part 53 of the coloredlayer. Therefore, the resulting shaped article exhibits a desired colortone expressed by the colored layer.

A manufacturing method for the shaped article 50′ of FIG. 9 ishereinafter described. The shaped article 50′ of FIG. 9 may bemanufactured by an inkjet head device 10′ illustrated in FIG. 10.

The inkjet head device 10′ illustrated in FIG. 10 has, on its lowersurface, roughly two inkjet heads 11H′ and 12H′. As illustrated in FIG.10, the first inkjet head 11H′ and the second inkjet head 12H′ aredisplaced from each other in both of the X and Y directions.

The first inkjet head 11H′ is the same as the first inkjet head 11Hillustrated in FIG. 3.

The second inkjet head 12H′ includes a white ink nozzle 10 (W) fordischarging a white ink (W) used to form the light reflective layer 1(parts 51 of the light reflective layer), and a transparent ink nozzle10 (CL) for discharging a transparent ink (CL).

The steps of manufacturing the shaped article 50′ using the inkjet headdevice 10′ are hereinafter described referring to FIG. 11.

In step S1′ illustrated in (a) of FIG. 11, the part 52 of the firsttransparent layer is formed from the transparent ink, and the part 51 ofthe light reflective layer is formed from the white ink (W). In thisstep, the inkjet head device 10′ is moved in a negative direction alongthe X axis, and the transparent ink is discharged at a predeterminedtiming through the transparent ink nozzle 10 (CL), and the white ink (W)is discharged at a predetermined timing through the white ink nozzle 10(W). The discharged inks land on a position at which the part 52 of thefirst transparent layer should be formed and a position at which thepart 51 of the light reflective layer should be formed. Then, thedischarged inks pooled at the respective positions are irradiated withultraviolet light to be cured. As a result, the part 52 of the firsttransparent layer and the part 51 of the light reflective layer areformed as illustrated in (a) of FIG. 11.

In step S2′ illustrated in (b) of FIG. 11 the inkjet head device 10′ ismoved in a positive direction along the X axis, and the colored layerfont ling inks including the coloring inks are discharged at apredetermined timing to land on a position at which the part 53 of thecolored layer should be formed. Then, the discharged ink pooled at theposition is irradiated with ultraviolet light to be cured.

As a result of steps S1′ and S2′, the formation of a layer 50′a iscompleted. The support material 60 described in the earlier embodimentis formed in the second modified example as well.

After the layer 50′a illustrated in (b) of FIG. 11 is formed, a newlayer 50′a is formed on the layer 50′a of (b) of FIG. 11 in stepssimilar to steps S1′ and S2′.

Specifically, step S3′ illustrated in (c) of FIG. 11 forms the part 52of the first transparent layer and the part 51 of the light reflectivelayer in a manner similar to step S1′. In step S3′, the upper layer 50′aneeds to be formed in a greater size (area) along the X-Y plane than thelower layer 50′a, as described in the earlier embodiment. To this end,as illustrated in (c) of FIG. 11, the transparent ink is discharged sothat the part 52 of the first transparent layer in the upper layer 50′aoverlaps the part 53 of the colored layer in the lower layer 50′aalready formed by the time when step S2′ is completed. At the same time,the white ink (W) is discharged and pooled so that the part 51 of thelight reflective layer in the upper layer 50′a overlaps the part 51 ofthe light reflective layer and the part 52 of the first transparentlayer in the lower layer 50′a. Then, the pooled ink is irradiated withultraviolet light to be cured.

In step S4′ illustrated in (d) of FIG. 11, the colored layer forminginks are discharged at a predetermined timing in a manner similar tostep S1′ to land on a position at which the part 53 of the colored layershould be formed and pooled at the position. The predetermined timingrefers to a timing of discharging the colored layer forming inks on theouter side of the part 52 of the first transparent layer in the upperlayer 50′a with no overlap with the part 53 of the colored layer in thelower layer 50′a. The pooled ink is irradiated with ultraviolet lightand thereby cured. Then, the part 53 of the colored layer in the upperlayer 50′a is formed.

By repeatedly forming and stacking the layers 50′a on one another, theshaped article 50′ illustrated in FIG. 9 may be manufactured.

Third Modified Example

In the embodiment described earlier, the shaped article 50 ismanufactured by the inkjet head device 10 illustrated in FIG. 3. In thesecond modified example, the shaped article 50′ is manufactured by theinkjet head device 10′ illustrated in FIG. 10. Instead of these inkjethead devices, inkjet head devices illustrated in FIG. 12 to FIG. 14 maybe used.

FIG. 12 is a drawing of a modified example of the inkjet head device,illustrated similarly to FIG. 3 and FIG. 10. In an inkjet head device 10a illustrated in FIG. 12, a cyan ink nozzle 10 (C), a magenta ink nozzle10 (M), a yellow ink nozzle 10 (Y), a black ink nozzle 10 (K), a whiteink nozzle 10 (W), and a transparent ink nozzle 10 (CL) are arranged inthe mentioned order in the X direction.

FIG. 13 is a drawing of another modified example of the inkjet headdevice, illustrated similarly to FIG. 3 and FIG. 10. In an inkjet headdevice 10 b illustrated in FIG. 13, a white ink nozzle 10 (W), atransparent ink nozzle 10 (CL), a yellow ink nozzle 10 (Y), a magentaink nozzle 10 (M), a cyan ink nozzle 10 (C), a black ink nozzle 10 (K),a transparent ink nozzle 10 (CL), and a white ink nozzle 10 (W) arearranged in the mentioned order in the X direction.

FIG. 14 is a drawing of yet another modified example of the inkjet headdevice. An inkjet head device 10 b illustrated in FIG. 14 has a carriage21 allowed to reciprocate along the X axis, a plurality of nozzle arraysmounted in the carriage 21, and ultraviolet irradiators 24 a and 24 bmounted in the carriage 21. The carriage 21 is moved in the Y directionto perform a scan, in which the inks of ultraviolet curing type aredischarged from the nozzle arrays and irradiated with ultraviolet lightemitted from the ultraviolet irradiators 24 a and 24 b.

The nozzle arrays are aligned along the X direction as illustrated inFIG. 14. From the left to right in the X direction on the drawing arearranged a cyan ink nozzle array C, a magenta ink nozzle array M, ayellow ink nozzle array Y, a black ink nozzle array K, a white inknozzle array W, and a transparent ink nozzle array CL are aligned in thementioned order. Since the nozzle arrays are mounted in the carriage 21,the inks of ultraviolet curing type are dischargeable from these nozzlearrays while moving in the X direction with the carriage 21.

Because all of the nozzles are aligned in the X direction in FIG. 12,FIG. 13, and FIG. 14, the formation of one layer may be completed bymoving the nozzles once in the X direction and discharging all of therequired ink during the movement. Referring to FIG. 14, all of the inksmay be discharged and irradiated with ultraviolet light by moving thenozzles just once in the X direction. This may also be applicable to alayer formed from the inks of ultraviolet curing type, which may becured as soon as the inks are discharged.

[Additional Remarks]

The shaped article 50 according to one aspect has the first transparentlayer 2 formed from the transparent ink between the light reflectivelayer 1 formed from the light reflective ink and the colored layer 3,wherein the colored layer 3, first transparent layer 2, and lightreflective layer 1 are formed in the mentioned order from theouter-layer side toward the inner side of the shaped article 50.

By interposing the first transparent layer 2 between the lightreflective layer 1 and the colored layer 3, intermixing of the coloringinks and the underlayer ink, if occurs, may be intermixing of thecoloring inks and the transparent ink of the first transparent layer 2,while avoiding intermixing of the coloring inks and the light reflectiveink. This may avoid any negative impact on the color tone of the coloredlayer 3 formed from the coloring inks. The shaped article 50 mayaccordingly exhibit a color tone as desired.

The shaped article 50 according to one aspect may be more advantageouswhen a white pigment-containing ink is used to form the light reflectivelayer 1, because rays of light entering from the outer-layer side of theshaped article may be better reflected by the white pigment-containingink.

The shaped article 50 according to one aspect further includes thesecond transparent layer 4 on the outer-layer side of the colored layer3.

The second transparent layer 4 may serve to protect the colored layer 3and may also contribute to elaborateness and high accuracy of the shapedarticle 50.

The shaped article 50 according to one aspect is further characterizedin that the colored layer 3 formed has its ink density filled by thetransparent ink in parts of the colored layer 3 in which the coloringinks alone are insufficient to meet a predetermined ink density.

By having the ink density of the colored layer 3 filled by thetransparent ink, the colored layer 3 may avoid any voids and unevenparts that would otherwise be generated. This may contribute to theformation of an elaborate and very accurate three-dimensional structure.

The shaped article 50 according to one aspect is further characterizedin that plural layers 50 a, 50′a are stacked on one another, a part ofthe colored layer 3 (part 53 of the colored layer), a part of the firsttransparent layer 2 (part 52 of the first transparent layer), and a partof the light reflective layer 1 (part 51 of the light reflective layer)are formed in at least one of the plural layers 50 a, 50′a in thementioned order from the end side toward the center side of the layer.

The shaped article 50 according to one aspect is further characterizedin that the second transparent layer 4 is formed on the outer-layer sideof the colored layer 3, and a part of the colored layer 3 (part 53 ofthe colored layer) in at least one of the plural layers 50 a, 50′a isinterposed between a part of the first transparent layer 2 (part 52 ofthe first transparent layer) and a part of the second transparent layer4 (part 54 of the second transparent layer).

The shaped article 50 according to one aspect is further characterizedin having a region in which the layers 50 a, 50′a are stacked on oneanother, each layer having a part of the colored layer 3 (part 53 of thecolored layer) between a part of the first transparent layer 2 (part 52of the first transparent layer) and a part of the second transparentlayer 4 (part 54 of the second transparent layer), and in a portion ofthe region with no overlap between a part of the colored layer 3 (part53 of the colored layer) in one of the layers 50 a, 50′a and a part ofthe colored layer 3 (part 53 of the colored layer) in another one of thelayers 50 a, 50′a on or below the one of the layers 50 a, 50′a, there isan overlap between a part of the colored layer 3 (part 53 of the coloredlayer) in one of the layers 50 a, 50′a and a part of the firsttransparent layer 2 (part 52 of the first transparent layer) or a partof the second transparent layer 4 (part 54 of the second transparentlayer) in another one of the layers 50 a, 50′a on or below the one ofthe layers 50 a, 50′a.

The manufacturing method for the shaped article 50 according to oneaspect is a manufacturing method for the shaped article 50 including thecolored layer 3, first transparent layer 2, and light reflective layer 1formed from the light reflective ink, wherein the colored layer 3, firsttransparent layer 2, and light reflective layer 1 are formed in thisorder from the outer-layer side toward the inner side of the shapedarticle 50. This method employs the multilayer lamination technique toform the layers. Further, the method includes a layer forming processincluding forming a part of the colored layer 3 (part 53 of the coloredlayer), a part of the first transparent layer 2 (part 52 of the firsttransparent layer), and a part of the light reflective layer 1 (part 51of the light reflective layer) in this order from the end side towardthe center side of each one of the layers 50 a, 50′a.

By interposing the first transparent layer 2 between the lightreflective layer 1 and the colored layer 3, intermixing of the coloringinks and the underlayer ink, if occurs, may be intermixing of thecoloring inks and the transparent ink of the first transparent layer 2,while avoiding intermixing of the coloring inks and the light reflectiveink. Intermixing of the coloring inks and the transparent ink, ifoccurs, may not adversely affect a desired color tone. The shapedarticle 50 may accordingly exhibit a color tone as desired.

The manufacturing method for the shaped article 50 according to oneaspect further includes forming the second transparent layer 4 on theouter-layer side of the colored layer 3, wherein the layer formingprocess includes forming a part of the second transparent layer 4 (part54 of the second transparent layer) at a position nearer to the end sidethan a part of the colored layer 3 (part 53 of the colored layer) ineach of the layers 50 a, 50′a formed.

In the shaped article in which the second transparent layer 4 is formedon the outer-layer side of the colored layer 3, the second transparentlayer 4 may serve to protect the colored layer 3 and may also contributeto elaborateness and high accuracy of the shaped article 50.

Specifically, by forming the second transparent layer (part 54 of thesecond transparent layer) before the colored layer (part 53 of thecolored layer) is formed in each of the layers 50 a, 50′a, the secondtransparent layer (part 54 of the second transparent layer) may serve asthe outer moat of the colored layer 3 (part 53 of the colored layer).This may prevent the ink forming the colored layer (part 53 of thecolored layer) from spreading unintendedly or dropping downward.

In the upper and lower layers 50 a, 50′a, the presence of the secondtransparent layer (part 54 of the second transparent layer) on the lowerlayer 50 a, 50′a may allow a larger formation area to be secured for thecolored layer (part 53 of the colored layer) on the upper layer 50 a,50′a. Such an increase of the colored layer formation area may preventthe risk with the layers 50 a, 50′a that the coloring inks applied toform the colored layer (part 53 of the colored layer) in one of thelayers run off an edge of another one of the layers therebelow, droppingdownward. Hence, the shaped article 50 may be successfully manufacturedas desired.

The manufacturing method for the shaped article 50 according to oneaspect is further characterized in that the layer forming process offorming the layer 50 a, 50′a includes steps of: forming a part of thecolored layer 3 (part 53 of the colored layer) using the coloring ink;forming a part of the first transparent layer 2 (part 52 of the firsttransparent layer) using the transparent ink; forming a part of thelight reflective layer 1 (part 51 of the light reflective layer) usingthe light reflective ink; and forming a part of the second transparentlayer 4 (part 54 of the second transparent layer) using the transparentink, wherein the step of forming a part of the colored layer 3 (part 53of the colored layer) from the coloring inks follows the step of forminga part of the first transparent layer (part 52 of the first transparentlayer) and the step of forming a part of the second transparent layer toform a part of the colored layer 3 (part 53 of the colored layer)between a part of the first transparent layer 2 (part 52 of the firsttransparent layer) and a part of the second transparent layer 4 (part 54of the second transparent layer).

By forming the first transparent layer (part 52 of the first transparentlayer) and the second transparent layer (part 54 of the secondtransparent layer) before the colored layer (part 53 of the coloredlayer) is formed, the first transparent layer (part 52 of the firsttransparent layer) and the second transparent layer (part 54 of thesecond transparent layer) may serve as the outer moat of the coloredlayer (part 53 of the colored layer). This may prevent the colored layer(part 53 of the colored layer) from spreading unintendedly. The shapedarticle 50, therefore, may be successfully manufactured as desired.

The manufacturing method for the shaped article 50 according to oneaspect is further characterized in that, in a portion with no overlapbetween a part of the colored layer 3 (part 53 of the colored layer) inone of the layers 50 a, 50′a and a part of the colored layer 3 (part 53of the colored layer) in another one of the layers 50 a, 50′a on orbelow the one of the layers 50 a, 50′a, there is an overlap between apart of the colored layer 3 (part 53 of the colored layer) in one of thelayers 50 a, 50′a and a part of the first transparent layer 2 (part 52of the first transparent layer) or a part of the second transparentlayer 4 (part 54 of the second transparent layer) in another one of thelayers 50 a, 50′a on or below the one of the layers 50 a, 50′a.

The colored layer (part 53 of the colored layer) may be interposed alsoin the layer-stacked direction between the transparent ink layers (part52 of the first transparent layer and part 54 of the second transparentlayer). This may avoid any overlap between parts of the colored layer(parts 53 of the colored layer) in the upper and lower layers 50 a,50′a. The shaped article 50 thus formed may not exhibit undesirablevariability in color tone when viewed in a certain direction and viewedin another direction inclined from the direction.

The manufacturing method for the shaped article 50 according to oneaspect is further characterized in forming a part of the decorativelayer by filling the ink density of the decorative layer using atransparent supplementary ink in a part of the decorative layer in whichdecorative inks alone are insufficient to meet a predetermined inkdensity. Thus, the ink density of the colored layer 3 (part 53 of thecolored layer) is filled by the transparent ink.

By having the ink density of the colored layer 3 (part 53 of the coloredlayer) filled by the transparent ink, the colored layer 3 (part 53 ofthe colored layer) may avoid any unintended voids and uneven parts thatwould otherwise be generated. This may contribute to elaborateness andhigh accuracy of the shaped article 50.

This disclosure is not necessarily limited to the embodiment describedso far and may be carried out in many other forms. The technical scopeof this disclosure encompasses any modifications within its scopedefined by the appended claims and embodiments obtained by variouslycombining the technical means disclosed herein. By variously combiningthe technical means disclosed in the embodiment and modified examples,additional technical features may be further presented.

Second Embodiment

The inventors of this application found a problem with the known inkjet3D molding. The problem is, irregularities and/or voids were generatedin layers formed from the decorative inks (coloring inks of, forexample, yellow, magenta, cyan, and black inks) when these inks and amolding ink were discharged by inkjet printing technique.

They studied what triggered the problem and finally found out that theamounts of decorative inks discharged were variable depending onintended decorative effects, which led to an insufficient ink density ofthe decorative layer failing to meet a predetermined ink density. As forcoloring as an example of decoration (recording of characters and imagesin colors through subtractive color mixture), it is coloring inks thatdecide the color tone of a colored layer. Naturally, the amounts ofcoloring inks discharged may differ from one color tone to anotherdesirably expressed. When the coloring inks are discharged in relativelysmall amounts, the ink density of the colored layer may fail to meet apredetermined ink density. The inventors were led to the fact that suchshortage of the ink density would cause the irregularities and/or voidsdescribed earlier. The irregularities and/or voids are desirably avoidedbecause they are likely to impair a color tone to be attained bydecoration and adversely affect the whole structure of a shaped article.

To address the issue, this disclosure is directed to providing a shapedarticle that may be decorated as desired and also shaped as desired, anda manufacturing method for such a shaped article.

To this end, a shaped article disclosed herein is a shaped articleformed by multilayer lamination technique, further characterized in thatthe shaped article has a decorative layer, and the decorative layer hasits ink density filled by a supplementary ink in parts of the decorativelayer in which decorative inks alone are insufficient to meet apredetermined ink density.

By forming the decorative layer using the decorative inks alone, the inkdensity of the decorative layer may be partly insufficient, failing tomeet a predetermined ink density. This may generate irregularitiesand/or voids in the decorative layer. The irregularities and/or voidsmay incur failure to obtain any desired shape of the shaped article inthe manufacturing process. On the other hand, the shaped articlecharacterized as described herein may eliminate the risk of suchirregularities and/or voids because the ink density of the decorativelayer is filled by the supplementary ink. The shaped article, therefore,may be successfully decorated as desired and also shaped as desired.

The shaped article disclosed herein according to an aspect is furthercharacterized in that the supplementary ink includes a transparent ink.

Using the transparent ink may be unlikely to adversely affect decorativeeffects expected for the decorative layer, thereby successfullyproviding a shaped article decorated as desired.

A manufacturing method for a shaped article disclosed herein is amanufacturing method that employs multilayer lamination technique toform a shaped article having a decorative layer, further characterizedin that the decorative layer has its ink density filled by asupplementary ink in parts of the decorative layer in which decorativeinks alone are insufficient to meet a predetermined ink density.

By forming the decorative layer using the decorative inks alone, the inkdensity of the decorative layer may be partly insufficient, failing tomeet a predetermined ink density. This may generate irregularitiesand/or voids in the decorative layer. The irregularities and/or voidsmay incur failure to obtain any desired shape of the shaped article inthe manufacturing process. This method, on the other hand, may eliminatethe risk of such irregularities and/or voids because the ink density ofthe decorative layer is filled by the supplementary ink. The shapedarticle, therefore, may be successfully decorated as desired and alsoshaped elaborately.

The shaped article manufacturing method disclosed herein is furthercharacterized in including a layer forming process including forminglayers each having a part of the decorative layer, in which one of thelayers is newly formed on another one of the layers so that the parts ofthe decorative layer in these layers are continuous and thereby form thedecorative layer, and the layer forming process further includes fillingthe ink density of the decorative layer using a supplementary ink inparts of the decorative layer in which decorative inks alone areinsufficient to meet a predetermined ink density.

This method fills the ink density of the decorative layer in parts ofthe decorative layer formed by the layer forming process. This methodthus advantageous may successfully form layers with neither irregularitynor void.

This disclosure provides a shaped article that may be decorated asdesired and also shaped as desired, and a manufacturing method for sucha shaped article.

An embodiment of a shaped article and a shaped article manufacturingmethod disclosed herein is hereinafter described referring to FIG. 1 toFIG. 8. The shaped article disclosed herein has a three-dimensionalstructure constructed of a laminate of layers (formed by multilayerlamination technique). In the embodiment hereinafter described, inkjetprinting technique is employed to manufacture the shaped article. Thisis, however, just an option presented in this disclosure. Thisdisclosure may be applicable to any kinds of manufacturing methods thatcan obtain a shaped article by leveraging the multilayer laminationtechnique and decorate its surface (recording of characters and imagesin colors).

[1] Structure of Shaped Article

FIG. 1 is a perspective view of an outer shape of a shaped article 50according to an embodiment. The shaped article 50 according to thisembodiment has a substantially cylindrical shape with a curved sidesurface bulging outward. The shaped article disclosed herein and theshaped article manufactured by the manufacturing method disclosed hereinmay not be limited to the shape illustrated in FIG. 1. There are manyother examples of the shape, including a hexahedral shape describedlater, a spherical shape, a hollow structure, a ring-like shape, and ahorseshoe-like shape.

The shaped article 50 according to this embodiment includes a secondtransparent layer, a colored layer (decorative layer) formed fromcolorant-containing inks (decorative ink), a first transparent layerformed from a transparent ink, and a light reflective layer formed froman ink having light reflectiveness, wherein these layers are formed inthe mentioned order from an outer-layer side (outer peripheral side)toward an inner side (center) of the shaped article 50. This is adistinctive technical feature of this disclosure. FIG. 1 is a drawing ofthe shaped article 50. In this drawing, a second transparent layer 4formed from a transparent ink, which is the outermost layer, can be seenon the curved side surface of the shaped article 50.

FIG. 2 is a cross-sectional view of the illustration of FIG. 1 takenalong a cutting-plane line A-A′. The cross-sectional view of the shapedarticle 50 illustrated in FIG. 2 is taken at a central position of theshaped article 50 along the X-Z plane of the XYZ coordinate systemillustrated in FIG. 1.

The embodiment of FIG. 2 presents an example of the shaped article 50having a three-dimensional structure formed by stacking 21 layers 50 aon one another in the Z direction. It should be understood that theshaped article 50 may include less than or more than 21 layers.

[2] Structures of Layers

FIG. 5 is a drawing of the X-Y plane of a layer 50 a in the vicinity ofa mid-stage of the shaped article 50. The layers 50 a each include apart 54 of the second transparent layer, a part 53 of the colored layer,a part 52 of the first transparent layer, and a part 51 of the lightreflective layer. These layers are formed in the mentioned order from anouter peripheral side toward a center side of the shaped article. If theshaped article 50 according to this embodiment is stated another way,the light reflective layer 1, which is the body of the shaped article,is coated with the first transparent layer 2, colored layer 3, andsecond transparent layer 4 in the mentioned order toward the outer-layerside (outer peripheral side). Each one of the layers 50 a has athickness in the Z direction (vertical direction in the drawing) between5 μm and 50 μm. This is an adequate range of thickness values formulticolor formation of the colored layer 3 using the subtractive colormixture. For example, a preferable range of thickness values is 10 μm to25 μm when layers are formed from inks of ultraviolet curing type byinkjet printing technique.

In this embodiment, the light reflective layer 1 is the body of theshaped article; however, the light reflective layer may or may notconstitute the body of the shaped article. Specifically, the shapedarticle may have, at its center, a body or a cavity apart from the lightreflective layer, wherein the light reflective layer, first transparentlayer, colored layer, and second transparent layer are formed in thementioned order from the body (may or may not have light reflectiveness)toward the outer-layer side (outer peripheral side). Alternatively, acore (may or may not have light reflectiveness) and the light reflectivelayer 1 formed on a surface of the core may be collectively regarded asthe body of the shaped article.

By stacking the layers 50 a in the Z direction as illustrated in FIG. 2,the parts 54 of the second transparent layer in the respective layers 50a are substantially continuous in a direction along the outermostsurface of the shaped article 50, forming the second transparent layer4. The parts 53 of the colored layer in the respective layers 50 a aresubstantially continuous in the direction along the outermost surface ofthe shaped article 50, forming the colored layer 3. The parts 52 of thefirst transparent layer in the respective layers 50 a are substantiallycontinuous in the direction along the outermost surface of the shapedarticle 50, forming the first transparent layer 2. The parts 51 of thelight reflective layer in the respective layers 50 a are substantiallycontinuous in the direction along the outermost surface of the shapedarticle 50, forming the light reflective layer 1.

Looking at, in any of the X, Y, and Z directions, the outer surface ofthe shaped article 50 including the second transparent layer, coloredlayer, first transparent layer, and light reflective layer arranged inthe mentioned order, a color tone produced by the subtractive colormixture may be visually recognized.

The parts 52 of the first transparent layer may preferably have adimension in the direction of X-Y plane slightly greater than the part53 of the colored layer vertically in contact with the parts 52. Thismay more reliably prevent intermixing of the inks forming the coloredlayer 3 and the light reflective layer 1.

The parts 54 of the second transparent layer may preferably have adimension in the direction of X-Y plane slightly greater than the parts53 of the colored layer vertically in contact with the parts 54 of thesecond transparent layer. This may provide for better protection of thecolored layer 3.

The width of the shaped article 50 along the Z direction (hereinaftermay be referred to as thickness or height in the Z direction) is notparticularly limited. The thickness (height) of the layer 50 a in the Zdirection may be optionally decided depending on the number of layers.As described later, this embodiment constructs the multilayeredstructure using the inkjet printing technique. Therefore, any feasiblevalues in the technique should be contemplated for the thickness of thelayer 50 a in the Z direction. When inks of ultraviolet curing type areapplied by inkjet printing technique to form the layers (describedlater), the layer 50 a may have a thickness ranging from 5 μm to 20 μmdepending on the sizes of ink droplets. As for a large-sized shapedarticle for which a high resolution is not particularly required, plurallayers may be formed based on the same data simply by increasing thesizes of ink droplets. In such a case, a smaller data volume and ahigher molding rate may be anticipated.

[3] Structure of Light Reflective Layer 1 (Parts 51 of Light ReflectiveLayer)

The light reflective layer 1 (parts 51 of the light reflective layer) isa layer formed from a light reflective ink. This layer, therefore, haslight reflectiveness that allows rays of light in the whole visiblelight region to be reflected on at least the surface of the lightreflective layer 1 in contact with the colored layer.

Specific examples of ink of the light reflective layer 1 (parts 51 ofthe light reflective layer) may include metallic powder-containing inksand white pigment-containing inks. The light reflective layer 1 maypreferably be formed from a white ink. The light reflective layer 1formed from a white ink may adequately reflect rays of light enteringfrom the outer-layer side of the shaped article, allowing the shapedarticle to be colored by the subtractive color mixture.

In this embodiment, the light reflective layer 1 constitutes the body ofthe shaped article. In case the light reflective layer 1 is formed onthe surface of the body of any shaped article for which lightreflectiveness is not required, the thickness of the light reflectivelayer 1, i.e., the width of the part 51 of the light reflective layerfrom the outer peripheral side to the center side, as illustrated inFIG. 2, may be between 5 μm and 20 μm at the least. The width in thisdisclosure may include but is not limited to the range of values.

[4] Structure of First Transparent Layer 2 (Parts 52 of FirstTransparent Layer)

The first transparent layer 2 (parts 52 of the first transparent layer)is formed from a transparent ink.

The transparent ink may refer to an ink capable of forming a transparentlayer having light transmittance greater than or equal to 50% per unitthickness. The light transmittance less than 50% per unit thickness ofthe transparent layer may unintendedly block the transmission of light.This may be a drawback that fails to exhibit a desired color tone of theshaped article by way of the subtractive color mixture. Preferably isused an ink having light transmittance greater than or equal to 80% perunit thickness of the transparent layer. Further, an ink having lighttransmittance greater than or equal to 90% per unit thickness of thetransparent layer is particularly preferable.

By interposing the first transparent layer 2 (part 52 of the firsttransparent layer) between the light reflective layer 1 (part 51 of thelight reflective layer) and the colored layer 3 (part 53 of the coloredlayer), intermixing of the coloring inks of the colored layer 3 and theink of the light reflective layer 1 may be avoidable. Even if thecoloring inks applied to form the colored layer are mixed with thetransparent ink of the first transparent layer, intermixing of theseinks may not adversely affect colors of the colored layer or cause anyundesirable change to the color tone. Therefore, the resulting shapedarticle exhibits a desired color tone (decorated as desired) expressedby the colored layer 3.

The width of the part 52 of the first transparent layer from the outerperipheral side to the center side (hereinafter, referred to as thethickness of the first transparent layer) is between 5 μm and 20 μm atthe least in a decorated portion on a surface perpendicular to thelayer-stacked direction. The width in this disclosure may include but isnot limited to the range of values.

[5] Structure of Colored Layer 3 (Part 53 of Colored Layer)

The colored layer 3 (part 53 of the colored layer) is formed from acolorant-containing coloring ink.

Examples of the colorant-containing inks (hereinafter may be referred toas coloring ink) may include but are not limited to yellow (Y), magenta(M), cyan (C), black (K), and pale color inks. Further, red (R), green(G), blue (B), and orange (Or) color inks may be additionally used.Other usable inks may include metallic, pearl, and phosphor inks. One ormore than one of these coloring inks may preferably be used to express adesired color tone.

The amounts of the coloring inks to form the colored layer 3 (parts 53of the colored layer) may be variable depending on a desired (desirablyexpressed) color tone. In case the coloring inks alone are used toexpress a bright color tone at a relatively low concentration, the inkdensity of the colored layer 3 may fail to meet a predetermined inkdensity. This may generate irregularities in the Z direction and/orink-less dented parts at positions along the X-Y direction. In any case,the shaped article formed by the multilayer lamination technique, asdescribed in this embodiment, may consequently have an irregular,unattractive shape, which is desirably avoided. In case onecross-sectional surface of the colored layer 3 has the ink density oftwo lateral and two vertical ink droplets; four ink droplets in total,formed by the error diffusion method on a vertical mold surface near themid position of the multilayered structure illustrated in FIG. 2, thecoloring inks each form four ink droplets at the most (largestconcentration) and no ink droplet at the least (zero concentration,meaning colorless). The number of ink droplets being zero may leave anunfilled space as large as four ink droplets, significantly degradingthe shaped article in view of its shape and color tone.

This embodiment, therefore, fills the ink density of the colored layer 3(part 53 of the colored layer) using a supplementary ink in parts of thecolored layer 3 (part 53 of the colored layer) in which the coloringinks alone are insufficient to meet a predetermined ink density.Specifically, the colored layer 3 (parts 53 of the colored layer) isformed at a constant total density (number of ink droplets) of thecoloring inks and the supplementary ink. This may successfully preventthe formation of dented parts, allowing the shaped article 50 to beelaborately shaped.

The amounts of the coloring inks to be discharged and their landingpositions are known beforehand, based on which the amount and position(landing position) of the supplementary ink to be additionallydischarged may be suitably determined. The amount and position may bedecided by an inkjet head device 10 or by a controller not illustratedin the drawings.

Having the ink density filled by the supplementary ink may allow asurface formed by the colored layer 3 to be flattened, impartingglossiness to the surface.

The supplementary ink may be any ink unless it adversely affects thecolor tone to be expressed by the colored layer 3 (parts 53 of thecolored layer). An example of the supplementary ink may be thetransparent ink used to form the first transparent layer 2 (parts 52 ofthe first transparent layer) and the second transparent layer 4 (parts54 of the first transparent layer).

The thickness of the colored layer 3, the width of the part 53 of thecolored layer from the outer peripheral side to the center sideillustrated in FIG. 2 (hereinafter, referred to as the thickness of thecolored layer 3) may be between 5 μm and 20 μm.

The colored layer 3 described in this embodiment is just an option andmay be any decorative layer.

[6] Structure of Second Transparent Layer 4 (Parts 54 of SecondTransparent Layer)

The second transparent layer 4 (parts 54 of the second transparentlayer) is formed from the same transparent ink as that of the firsttransparent layer 2 (parts 52 of the first transparent layer). The sametransparent ink or different transparent inks may be used to form thesecond transparent layer 4 and the first transparent layer 2.

The thickness of the second transparent layer 4, i.e., the width of thepart 54 of the second transparent layer from the outer peripheral sideto the center side illustrated in FIG. 2 (hereinafter, referred to asthe thickness of the second transparent layer 4) may be between 10 μmand 100 μm.

The second transparent layer 4 functions as a protective layer for thecolored layer 3. In this disclosure that employs the multilayerlamination technique (this embodiment), the second transparent layer 4may also advantageously contribute to elaborateness of the shapedarticle.

Supposing that the colored layer 3 is the outermost layer of the shapedarticle 50, i.e., the parts 53 of the colored layer are located at thefarthest ends of the respective layers 50 a illustrated in FIG. 2, thecolored layer 3 (parts 53 of the colored layer) formed may not be asaccurate as expected. On the other hand, the shaped article 50 whoseoutermost layer is the second transparent layer 4 (parts 54 of thesecond transparent layer), as described in this embodiment, may ensurethe accuracy of the colored layer 3 (parts 53 of the colored layer).Thus, the second transparent layer 4 (parts 54 of the second transparentlayer) may greatly contribute to a desired color tone.

Another disadvantage in case the colored layer 3 is the outermost layerof the shaped article 50 is that the exposed colored layer 3 may beprone to decolorization under friction and color fading by exposure toultraviolet. However, as described in this embodiment, the shapedarticle 50 whose outermost layer is the second transparent layer 4(parts 54 of the second transparent layer) may prevent such unfavorableevents as decolorization and color fading.

[7] Manufacturing Method for Shaped Article

A manufacturing method for the shaped article 50 according to thisembodiment is hereinafter described. FIG. 3 is a drawing of the lowersurface of the inkjet head device 10 used in the manufacturing method.FIG. 4 shows schematic drawings of ongoing steps of manufacturing theshaped article 50 according to this embodiment.

The inkjet head device 10 has, on its lower surface, roughly threeinkjet heads 11H to 13H. As illustrated in FIG. 3, the first inkjet head11H, second inkjet head 12H, and third inkjet head 13H are displacedfrom one another in the X direction. As illustrated in FIG. 3, the firstinkjet head 11H, second inkjet head 12H, and third inkjet head 13H arealso displaced from one another in the Y direction. Thus, the inkjetheads 11H to 13H are positioned in, generally called, staggeredarrangement.

The first inkjet head 11H has a cyan ink nozzle 10 (C) for discharging acyan ink, a magenta ink nozzle 10 (M) for discharging a magenta ink, ayellow ink nozzle 10 (Y) for discharging a yellow ink, and a black inknozzle 10 (K) for discharging a black ink. The number and the order ofarrangement of the nozzles 10 (C), 10 (M), 10 (Y), and 10 (K) are notlimited to the example illustrated in FIG. 3. All of the inks dischargedthrough these nozzles are coloring inks used to form the colored layer 3(parts 53 of the colored layer) illustrated in FIG. 2.

The second inkjet head 12H has a white ink nozzle 10 (W) for discharginga white ink (W). The white ink (W) is an ink used to form the lightreflective layer 1 (parts 51 of the light reflective layer) illustratedin FIG. 2.

The third inkjet head 13H has a transparent ink nozzle 10 (CL) fordischarging a transparent ink (CL). The transparent ink (CL) is an inkused to form the first transparent layer 2 (parts 52 of the firsttransparent layer) and the second transparent layer 4 (parts 54 of thesecond transparent layer) illustrated in FIG. 2.

The inkjet head device 10 is located so as to have its lower surfaceillustrated in FIG. 3 face the layer 50 a currently being formed. Theinkjet head device 10 is configured to reciprocate in the X directionand discharge the inks while moving in the direction. The inkjet headdevice 10 is moved in a predetermined direction in an XYZ coordinatesystem, or a table with the layers 50 a placed thereon (FIG. 4 shows alayer formation surface B of the table) is moved in a predetermineddirection in the XYZ coordinate system to change relative positions ofthe inkjet head device 10 and the layer 50 a currently being formed.Which one of them should be moved may be optionally decided.

Each of the inks is an ink of ultraviolet curing type that needs to beirradiated with ultraviolet light after being discharged. A ultravioletirradiator may be mounted in the inkjet head device 10 or may beinstalled as a separate device. The inks are cured by being irradiatedwith ultraviolet light to form the layers 50 a illustrated in FIG. 2.

The manufacturing process for the shaped article 50 using the inkjethead device 10 is hereinafter described referring to FIG. 4.

To start with, a first one of the layers 50 a (first layer 50 a (1)) isforming on the layer formation surface B of the table.

In the step of forming (manufacturing) the first layer 50 a (1), byusing the inkjet printing technique, the respective inks are dischargedfrom the inkjet head device 10 at predetermined timings to form a partof the second transparent layer, a part of the colored layer, a part ofthe first transparent layer, and a part of the light reflective layer inthe mentioned order from the end side toward the center side of thefirst layer 50 a.

The steps of forming (manufacturing) the first layer 50 a (1) aredescribed in further detail referring to (a)˜(c) of FIG. 4.

In step S1 illustrated in (a) of FIG. 4, the part 54 of the secondtransparent layer is formed from the transparent ink, and the part 52 ofthe first transparent layer is formed from the transparent ink. In thisstep, the inkjet head device 10 is moved in a positive direction alongthe X axis, and the transparent ink is discharged at a predeterminedtiming through the transparent ink nozzle 10 (CL) illustrated in FIG. 3.The discharged ink lands on a position at which the part 54 of thesecond transparent layer should be formed and a position at which thepart 52 of the first transparent layer should be formed. Then, thedischarged ink pooled at the respective positions is irradiated withultraviolet light to be cured. As a result, the part 52 of the firsttransparent layer and the part 54 of the second transparent layer areformed as illustrated in (a) of FIG. 4.

In step S2 illustrated in (b) of FIG. 4, the inkjet head device 10 ismoved in a negative direction along the X axis, and the white ink (W),which is the light reflective ink, is discharged at a predeterminedtiming through the white ink nozzle 10 (W). Then, the discharged inkpooled there is irradiated with ultraviolet light to be cured. As aresult, the part 51 of the light reflective layer is formed asillustrated in (b) of FIG. 4.

In step S3 illustrated in (c) of FIG. 4, the inkjet head device 10 ismoved in the positive direction along the X axis, and the colored layerforming inks including the coloring inks and the supplementary ink aredischarged at a predetermined timing so that the total amount of theseinks discharged is constant, and then irradiated with ultraviolet light.The predetermined timing refers to a timing at which the nozzles of thefirst inkjet head 11H are located at positions at which the coloredlayer forming inks are dischargeable in a region between the part 52 ofthe first transparent layer and the part 54 of the second transparentlayer formed in step S1. The ink droplets in a predetermined amount aredischarged by inkjet printing technique at this timing to form a pool ofink. Then, the pooled ink is irradiated with ultraviolet light to becured. This forms the part 53 of the colored layer exhibiting a desiredcolor tone between the part 52 of the first transparent layer and thepart 54 of the second transparent layer as illustrated in (c) of FIG. 4.

As a result of steps S1 to S3, the formation of the first layer 50 a (1)is completed. The first layer 50 a (1) has the same structure asillustrated in the upper view of the layer 50 a in FIG. 5. Optionally,step 1 and step 2 may be performed in the reversed order. Likewise, stepS2 and step S3 may be performed in the reversed order.

After the first layer 50 a (1) is formed, a new layer 50 a (second layer50 a (2)) is formed on the first layer 50 a (1) (laminate of layers).

In the shaped article 50 according to this embodiment, the layers 50 astacked on one another along the X-Y plane are progressively increasedin size (area) from the bottom toward the mid stage of the multilayeredbody as illustrated in FIG. 2. In the shaped article 50 manufactured insuch a shape that increases in size along the layer-stacked directionwhen viewed in cross section, the end of one layer 50 a is sticking outsideways further than the end of another layer 50 a already formed belowthe one layer 50 a. To form the layers 50 a thus characterized, supportmaterial layers may preferably be formed.

In FIG. 4, (d) is a drawing of the step of forming the second layer 50 a(2). Referring to this drawing, a part 53 (2) of the colored layer inthe second layer 50 a (2) is formed so as to overlap a part 54 (1) ofthe second transparent layer in the first layer 50 a (1). Since thesecond layer 50 a (2) is greater in size (area) along the X-Y plane thanthe first layer 50 a (1), the part 54 (2) of the second transparentlayer forming the end of the second layer 50 a (2) is sticking outsideways further than the part 54 (1) of the second transparent layerforming the end of the first layer 50 a (1). Because of this structure,the ink to be deposited on a part of the layer 50 a (2) where thestick-out part should be formed possibly runs off this part and dropsdownward. To avoid that, a support material 60 is formed on the outerside (on the lateral side) than the part 54 (1) of the secondtransparent layer in the first layer 50 a (1).

The support material 60 may preferably be formed from any ink that canbe discharged by inkjet printing technique. The support material 60should preferably have enough strength not to collapse under the weightof another layer formed thereon. The support material 60 per se will notbe left in the finalized shaped article 50. The ink forming the supportmaterial 60, therefore, should preferably be selected from inks that canbe stripped off afterwards. The ink of the support material 60 maypreferably be curable by ultraviolet light (to a degree of cure at whichthe ink is stripped off in subsequent steps), or may be a water-solubleink that can be dissolved in water and removed in subsequent steps.

The steps of forming the layers 50 a are repeatedly performed in the Xand Y directions as many times as required to form one layer, and thenrepeatedly performed again in the Z direction. As a result, the shapedarticle 50 illustrated in FIG. 2 is finally obtained. During the stepsof forming one layer, the known interlace scan conventionally employedto form two-dimensional images may preferably be performed to obtain ashaped article with less unevenness in shape and favorably decorated.

The shaped article manufacturing method according to this embodiment isfurther characterized in that the layer forming process includes stepsof: forming the part 54 of the second transparent layer using thetransparent ink; forming the part 53 of the colored layer using thecoloring inks; forming the part 52 of the first transparent layer usingthe transparent ink; and forming the part 51 of the light reflectivelayer using the light reflective ink, wherein the step of forming thepart 53 of the colored layer is performed subsequent to the step offorming the part 52 of the first transparent layer and the step offorming the part 54 of the second transparent layer to form the part 53of the colored layer between the part 52 of the first transparent layerand the part 54 of the second transparent layer. When the part 53 of thecolored layer is formed, the part 54 of the second transparent layer mayserve as the outer moat of the pooled inks to form the colored layer.This may prevent the ink of the colored layer from spreadingunintendedly, ensuring a high accuracy of the part 53 of the coloredlayer.

Further benefits delivered by forming the part 54 of the secondtransparent layer are described referring to FIG. 6 and FIG. 7. FIG. 6is a drawing of a part of the shaped article 50 according to thisembodiment, which is the part of (d) of FIG. 4 from which the supportmaterial has been removed. FIG. 7 is a cross-sectional view of a shapedarticle for comparison. The shaped article for comparison is formed bythe multilayer lamination technique similarly to the shaped article 50according to this embodiment. Unlike the shaped article 50, however,this shaped article lacks parts corresponding to the part 52 of thefirst transparent layer and the part 54 of the second transparent layer.In this shaped article for comparison, therefore, the light reflectivelayer is directly coated with the colored layer. Provided that the upperlayer is larger in size (area) along the X-Y plane than the lower layerin the shaped article for comparison, problems with this shaped articleare described.

In the shaped article for comparison illustrated in FIG. 7, the end ofthe upper layer includes a colored layer 152 (2). The colored layer 152(2) is sticking out further than a colored layer 152 (1) formed on theend of the lower layer. This shaped article, therefore, involves therisk that the inks for the colored layer discharged to form thestick-out part run off a coloring position and drop downward.

The colored layer is the deciding factor for the color tone of theshaped article. Therefore, thus losing the inks of the colored layer maycause an intended color tone of the shaped article to change.

On the other hand, the shaped article 50 according to this embodimentillustrated in FIG. 6 has the parts 54 of the second transparent layerat the ends of the layers 50 a. The ink applied to form the parts 54 ofthe second transparent layer, even if it falls downward in FIG. 6, maynot adversely affect a color tone desirably expressed because thecolored layer is the deciding factor for the color tone. This embodimentmay thus successfully manufacture the shaped article 50 that excels inreliability and exhibits a desired color tone.

There are other benefits as well. One of them is, forming the part 54 ofthe second transparent layer in the first layer 50 a (1) allow a largerformation area (formation allowable region) to be secured for thecolored layer of the second layer 50 a (2). This may help to mitigate ademanded degree of manufacturing accuracy to some extent, conducing toan improved manufacturing efficiency.

The ability to secure a larger formation area is advantageouslyeffective even if the part 54 of the second transparent layer is formedsubsequent to the part 53 of the colored layer. This disclosure,therefore, further includes forming the part 54 of the secondtransparent layer subsequent to the part 53 of the colored layer.

In the shaped article 50 according to this embodiment, the surface ofthe colored layer 3 is coated with the second transparent layer 4. Thesecond transparent layer 4 thus serves as the protective layer of thecolored layer 3.

FIG. 4 illustrates an example in which the upper layer is greater insize (area) along the X-Y plane than the lower layer. This examplerefers to the lower half of the shaped article 50 of FIG. 1 split in twohalves.

The manufacturing method described so far is basically applicable to theupper-half structure of the shaped article 50 of FIG. 1 split in twohalves. As for the upper half of the shaped article 50, as illustratedin FIG. 2, the upper colored layer is nearer to the center side of thelayer 50 a than the lower colored layer, and the parts 53 of the uppercolored layer overlap the parts 52 of the lower first transparent layer.Further, the parts 54 of the upper second transparent layer overlap theparts 53 of the lower colored layer.

In the upper half of the shaped article 50, as illustrated in FIG. 2,the lower layers are greater in size (area) along the X-Y plane than theupper layers formed thereon. In this upper-half structure, the inkapplied to form the colored layer in the upper layers is very unlikelyto drop downward. No support material may be necessary at the time ofmanufacturing the upper-half structure.

In the shaped article of FIG. 2 according to this embodiment, the bottomlayer and layers nearby, and the top layer and layers nearby include: alayer solely having the part 52 of the first transparent layer, part 53of the colored layer, and part 54 of the second transparent layer; alayer solely having the part 53 of the colored layer and the part 54 ofthe second transparent layer; and a layer solely having the part 54 ofthe second transparent layer. This multilayered structure may effectuatea shaped article whose entire surface is covered with the secondtransparent layer 4, colored layer 3, and first transparent layer 2.This disclosure, however, is not limited to such a multilayeredstructure. For example, the top and bottom surfaces of the shapedarticle may include none of the second transparent layer, colored layer,or first transparent layer, as in the multilayered structure of FIG. 9described later.

[8] Modified Example First Modified Example

The shaped article 50 according to this embodiment includes the firsttransparent layer 2, colored layer 3, and second transparent layer 4that are formed along the surface of the light reflective layer 1.However, this disclosure may include but is not limited to such astructure, and may optionally have a shaped article illustrated in FIG.8.

In the shaped articles illustrated in (a)˜(d) of FIG. 8, the secondtransparent layer 4 may have a shape described below instead of theshape along the surface of the light reflective layer 1. Because theparts 54 of the second transparent layer constitute the ends of thelayers 50 a (FIG. 2), the second transparent layer 4 may be formed in anadequate shape that contains therein the shaped article (structuredescribed in the earlier embodiment including the colored layer 3, firsttransparent layer, and light reflective layer), as illustrated in(a)˜(d) of FIG. 8.

Containing the shaped article in the shape formed by the secondtransparent layer 4, as described in this first modified example, may beuseful for any shaped articles that are mechanically fragile. Forexample, this modified example may be effectively applicable when, forexample, molding insects' legs and wings, and stems and petals offlowering plants. When molding organisms and plants in the form ofdecorative ornaments or specimens, they can be scanned alive by athree-dimensional scanner and released again into the nature when themolding is over. A further benefit may be eco-friendliness because nosupport material is necessary, producing no waste material.

In the shaped article illustrated in (a) of FIG. 8, the secondtransparent layer 4 has a hexahedral shape that contains a sphericalbody including the colored layer 3, first transparent layer, and lightreflective layer. The structure illustrated in (a) of FIG. 8 may beobtained by a manufacturing method similar to the method of FIG. 4.

In FIG. 8, (b) illustrates a shaped article 50 of frame-mounted type,wherein a figure including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4. This is a free-standing shaped article 50 supported by the secondtransparent layer 4. This shaped article 50 of frame-mounted type may bemanufactured (fabricated) by the manufacturing method described in theearlier embodiment.

In FIG. 8, (c) illustrates a shaped article 50 for use as a strap,wherein a figure including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4, and a hole 70 is formed in a part of the second transparent layer 4.This may be used as a strap or a key holder attachable to, for example,a mobile telephone. The hole 70 of the second transparent layer 4 may beformed at the same time when the outer shape is formed by the secondtransparent layer 4. By punching a hole in the second transparent layer4, the figure including the colored layer 3, first transparent layer,and light reflective layer can avoid being damaged with a hole.

In the shaped article 50 illustrated in (d) of FIG. 8, the upper-half ofa figure's body including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4. This article 50 has, on the surface or inside of the secondtransparent layer 4, a three-dimensional image 71 decorated with a markor a frame or painted in a pale color. This shaped article 50 furtherhas, on the surface or inside of the second transparent layer 4, aletter/character area 72 with letters and/or characters representingdate, name, or place. The decorated three-dimensional image 71 and theletter/character area 72 may be formed at the same time when the outershape is formed by the second transparent layer 4. Instead of thedecorated three-dimensional image 71 and the letter/character area 72,other additional information may be displayed on the surface or insideof the second transparent layer 4.

In (b)˜(d) of FIG. 8, one figure is contained in the second transparentlayer 4, however, the number of figures containable in the secondtransparent layer 4 may be other than one.

In case the shaped article according to this embodiment has a ring-likeshape, the colored layer may be formed near an inner peripheral end ofthe ring shape as well as an outer peripheral end thereof. Inconclusion, the colored layer may be formed on the surface of the shapedarticle, and the second transparent layer may be further formed thereon.

Instead of forming the second transparent layer 4 in any desired shapeas described in this modified example, the second transparent layer 4may be formed in a shape suitable for the surface of the lightreflective layer 1 similarly to the earlier embodiment. In that case,the obtained shaped article may be sealed in an optionally-shaped resin.

Second Modified Example

The shaped article 50 according to this embodiment has the secondtransparent layer 4 on its outermost side. This disclosure may achieveits goal in so far as the first transparent layer is interposed betweenthe colored layer and the light reflective layer. This disclosure,therefore, may include, as an embodiment, a shaped article 50′illustrated in cross section in FIG. 9. A second modified example ishereinafter described referring to FIG. 9 to FIG. 11. FIG. 9 is across-sectional view of the shaped article 50′ according to the secondmodified example, illustrated similarly to FIG. 2. FIG. 10 is aschematic drawing of the lower surface of an inkjet head deviceaccording to the second modified example used in manufacturing of theshaped article 50′. FIG. 11 shows drawings of manufacturing steps forthe shaped article 50′ according to the second modified example.

A difference between the shaped article 50′ according to the secondmodified example and the shaped article 50 according to the earlierembodiment is that the shaped article 50′ according to the secondmodified example has the colored layer 3 as its outermost layer, unlikethe shaped article 50 whose outermost layer is the second transparentlayer 4.

Referring to FIG. 9, layers 50′a constituting the shaped article 50′according to the second modified example include no part 54 of thesecond transparent layer, unlike the layers 50 a according to theearlier embodiment (FIG. 2) having these parts 54 at their ends.

In the layers 50′a of the shaped article 50′ illustrated in FIG. 9, theparts 52 of the first transparent layer are interposed between the parts53 of the colored layer and the parts 51 of the light reflective layer.This may prevent the coloring inks applied to form the parts 53 of thecolored layer from blending into the ink of the parts 51 of the lightreflective layer. Even if the coloring inks of the part 53 of thecolored layer are mixed with the transparent ink of the part 52 of thefirst transparent layer, intermixing of these inks may cause noundesirable change to the color tone of the part 53 of the coloredlayer. Therefore, the resulting shaped article exhibits a desired colortone expressed by the colored layer.

A manufacturing method for the shaped article 50′ of FIG. 9 ishereinafter described. The shaped article 50′ of FIG. 9 may bemanufactured by an inkjet head device 10′ illustrated in FIG. 10.

The inkjet head device 10′ illustrated in FIG. 10 has, on its lowersurface, roughly two inkjet heads 11H′ and 12H′. As illustrated in FIG.10, the first inkjet head 11H′ and the second inkjet head 12H′ aredisplaced from each other in both of the X and Y directions.

The first inkjet head 11H′ is the same as the first inkjet head 11Hillustrated in FIG. 3.

The second inkjet head 12H′ includes a white ink nozzle 10 (W) fordischarging a white ink (W) used to form the light reflective layer 1(parts 51 of the light reflective layer), and a transparent ink nozzle10 (CL) for discharging a transparent ink (CL).

The steps of manufacturing the shaped article 50′ using the inkjet headdevice 10′ are hereinafter described referring to FIG. 11.

In step S1′ illustrated in (a) of FIG. 11, the part 52 of the firsttransparent layer is formed from the transparent ink, and the part 51 ofthe light reflective layer is formed from the white ink (W). In thisstep, the inkjet head device 10′ is moved in a negative direction alongthe X axis, and the transparent ink is discharged at a predeterminedtiming through the transparent ink nozzle 10 (CL), and the white ink (W)is discharged at a predetermined timing through the white ink nozzle 10(W). The discharged inks land on a position at which the part 52 of thefirst transparent layer should be formed and a position at which thepart 51 of the light reflective layer should be formed. Then, thedischarged inks pooled at the respective positions are irradiated withultraviolet light to be cured. As a result, the part 52 of the firsttransparent layer and the part 51 of the light reflective layer areformed as illustrated in (a) of FIG. 11.

In step S2′ illustrated in (b) of FIG. 11, the inkjet head device 10′ ismoved in a positive direction along the X axis, and the colored layerforming inks including the coloring inks are discharged at apredetermined timing to land on a position at which the part 53 of thecolored layer should be formed. Then, the discharged ink pooled at theposition is irradiated with ultraviolet light to be cured.

As a result of steps S1 and S2, the formation of a layer 50′a iscompleted. The support material 60 described in the earlier embodimentis formed in the second modified example as well.

After the layer 50′a illustrated in (b) of FIG. 11 is formed, a newlayer 50′a is formed on the layer 50′a of (b) of FIG. 11 in stepssimilar to steps S1′ and S2′.

Specifically, step S3′ illustrated in (c) of FIG. 11 forms the part 52of the first transparent layer and the part 51 of the light reflectivelayer in a manner similar to step S1′. In step S3′, the upper layer 50′aneeds to be formed in a greater size (area) along the X-Y plane than thelower layer 50′a, as described in the earlier embodiment. To this end,as illustrated in (c) of FIG. 11, the transparent ink is discharged sothat the part 52 of the first transparent layer in the upper layer 50′aoverlaps the part 53 of the colored layer in the lower layer 50′aalready formed by the time when step S2′ is completed. At the same time,the white ink (W) is discharged and pooled so that the part 51 of thelight reflective layer in the upper layer 50′a overlaps the part 51 ofthe light reflective layer and the part 52 of the first transparentlayer in the lower layer 50′a. Then, the pooled ink is irradiated withultraviolet light to be cured.

In step S4′ illustrated in (d) of FIG. 11, the colored layer forminginks are discharged at a predetermined timing in a manner similar tostep S1′ to land on a position at which the part 53 of the colored layershould be formed and pooled at the position. The predetermined timingrefers to a timing of discharging the colored layer forming inks on theouter side of the part 52 of the first transparent layer in the upperlayer 50′a with no overlap with the part 53 of the colored layer in thelower layer 50′a. The pooled ink is irradiated with ultraviolet lightand thereby cured. Then, the part 53 of the colored layer in the upperlayer 50′a is formed.

By repeatedly forming and stacking the layers 50′a on one another, theshaped article 50′ illustrated in FIG. 9 may be manufactured.

Third Modified Example

In the embodiment described earlier, the shaped article 50 ismanufactured by the inkjet head device 10 illustrated in FIG. 3. In thesecond modified example, the shaped article 50′ is manufactured by theinkjet head device 10′ illustrated in FIG. 10. Instead of these inkjethead devices, inkjet head devices illustrated in FIG. 12 to FIG. 14 maybe used.

FIG. 12 is a drawing of a modified example of the inkjet head device,illustrated similarly to FIG. 3 and FIG. 10. In an inkjet head device 10a illustrated in FIG. 12, a cyan ink nozzle 10 (C), a magenta ink nozzle10 (M), a yellow ink nozzle 10 (Y), a black ink nozzle 10 (K), a whiteink nozzle 10 (W), and a transparent ink nozzle 10 (CL) are arranged inthe mentioned order in the X direction.

FIG. 13 is a drawing of another modified example of the inkjet headdevice, illustrated similarly to FIG. 3 and FIG. 10. In an inkjet headdevice 10 b illustrated in FIG. 13, a white ink nozzle 10 (W), atransparent ink nozzle 10 (CL), a yellow ink nozzle 10 (Y), a magentaink nozzle 10 (M), a cyan ink nozzle 10 (C), a black ink nozzle 10 (K),a transparent ink nozzle 10 (CL), and a white ink nozzle 10 (W) arearranged in the mentioned order in the X direction.

FIG. 14 is a drawing of yet another modified example of the inkjet headdevice. An inkjet head device 10 b illustrated in FIG. 14 has a carriage21 allowed to reciprocate along the X axis, a plurality of nozzle arraysmounted in the carriage 21, and ultraviolet irradiators 24 a and 24 bmounted in the carriage 21. The carriage 21 is moved in the Y directionto perform a scan, in which the inks of ultraviolet curing type aredischarged from the nozzle arrays and irradiated with ultraviolet lightemitted from the ultraviolet irradiators 24 a and 24 b.

The nozzle arrays are aligned along the X direction as illustrated inFIG. 14. From the left to right in the X direction on the drawing arearranged a cyan ink nozzle array C, a magenta ink nozzle array M, ayellow ink nozzle array Y, a black ink nozzle array K, a white inknozzle array W, and a transparent ink nozzle array CL are aligned in thementioned order. Since the nozzle arrays are mounted in the carriage 21,the inks of ultraviolet curing type are dischargeable from these nozzlearrays while moving in the X direction with the carriage 21.

Because all of the nozzles are aligned in the X direction in FIG. 12,FIG. 13, and FIG. 14, the formation of one layer may be completed bymoving the nozzles once in the X direction and discharging all of therequired ink during the movement. Referring to FIG. 14, all of the inksmay be discharged and irradiated with ultraviolet light by moving thenozzles just once in the X direction. This may also be applicable to alayer formed from the inks of ultraviolet curing type, which may becured as soon as the inks are discharged.

[Additional Remarks]

The shaped article 50 according to one aspect is a shaped article 50formed by the multilayer lamination technique and having the coloredlayer 3. This shaped article is further characterized in that thecolored layer 3 has its ink density filled by the supplementary ink inparts of the colored layer 3 in which the coloring inks alone areinsufficient to meet a predetermined ink density.

By forming the colored layer using the coloring inks alone, the inkdensity of the colored layer may be partly insufficient, failing to meeta predetermined ink density. This may generate irregularities and/orvoids in the decorative layer. The irregularities and/or voids may incurfailure to obtain any desired shape of the shaped article in themanufacturing process. On the other hand, the shaped article 50according to one aspect may eliminate the risk of such irregularitiesand/or voids because the ink density of the colored layer 3 is filled bythe supplementary ink. This may allow the shaped article 50 to exhibit adesired color tone (decorated as desired) and allow the shaped article50 to be shaped as desired.

The shaped article 50 according to one aspect is further characterizedin that the supplementary ink includes a transparent ink. Using thetransparent ink may be unlikely to adversely affect decorative effectsexpected for the colored layer, successfully providing a shaped articleexhibiting a desired color tone.

A manufacturing method for the shaped article 50 according to one aspectis a manufacturing method that employs the multilayer laminationtechnique to form the shaped article having the colored layer 3, furthercharacterized in that the colored layer 3 has its ink density filled bythe supplementary ink in parts of the colored layer 3 in which coloringinks alone are insufficient to meet a predetermined ink density.

By forming the colored layer using the coloring inks alone, the inkdensity of the colored layer may be partly insufficient, failing to meeta predetermined ink density. This may generate irregularities and/orvoids in the decorative layer. The irregularities and/or voids may incurfailure to obtain any desired shape of the shaped article in themanufacturing process. The method according to one aspect, on the otherhand, may eliminate the risk of such irregularities and/or voids becausethe ink density of the colored layer 3 is filled by the supplementaryink. This may allow the shaped article 50 to exhibit a desired colortone (decorated as desired) and allow the shaped article 50 to be shapedas desired.

The manufacturing method for the shaped article 50 according to oneaspect is further characterized in including a layer forming processincluding forming layers 50 a each including a part 53 of the coloredlayer, in which one of the layers 50 a is newly formed on another one ofthe layers 50 a so that the parts 53 of the colored layer in theselayers are continuous and thereby form the colored layer 3, and thelayer forming process further includes filling the ink density of thecolored layer using the supplementary ink in the parts 53 of the coloredlayer in which the coloring inks alone are insufficient to meet apredetermined ink density.

This method fills the ink density of the colored layer in the parts 53of the colored layer formed by the layer forming process. This methodthus advantageous may successfully form layers with neither irregularitynor void.

This disclosure is not necessarily limited to the embodiment describedso far and may be carried out in many other forms. The technical scopeof this disclosure encompasses any modifications within its scopedefined by the appended claims and embodiments obtained by variouslycombining the technical means disclosed herein. By variously combiningthe technical means disclosed in the embodiment and modified examples,additional technical features may be further presented.

Third Embodiment

The inventors of this application found a problem with the known inkjet3D molding when a molding ink and decorative inks (coloring inks of, forexample, yellow, magenta, cyan, and black inks) were discharged byinkjet printing technique. The problem is that a shaped article may failto be decorated as desired (recording of characters and images in colorsthrough subtractive color mixture). They studied what triggered thisproblem, and found out that, when forming a decorative layer formed fromdecorative inks as the outermost layer of a shaped article, thedecorative inks for the decorative layer discharged in the gravitationaldirection (downward) would possibly fail to arrive at a target position,dropping downward.

To address the issue, this disclosure is directed to providing a shapedarticle that may be decorated as desired, and a manufacturing method forsuch a shaped article.

A shaped article disclosed herein includes: a light reflective layerformed from an ink having light reflectiveness; a decorative layer; anda transparent layer formed from a transparent ink, wherein thedecorative layer is formed on an outer side of the light reflectivelayer, and the transparent layer is formed on an outer side of thedecorative layer.

In this shaped article, a larger formation area including an areaoverlapping a part of the transparent layer in addition to an areaoverlapping a part of the decorative layer in the lower layer may besecured for a part of the decorative layer in the upper layer, ascompared to layers lacking the parts of the transparent layer atpositions nearer to the end side than the parts of the decorative layer.This may help to mitigate a demanded degree of manufacturing accuracy tosome extent, contributing to an improved manufacturing efficiency.

To this end, a shaped article manufacturing method disclosed herein is amanufacturing method for manufacturing a shaped article by stacking aplurality of layers on one another, the shaped article including: atransparent layer formed from a transparent ink; and a decorative layer,wherein the transparent layer and the decorative layer are formed inthis order from an outer-layer side toward an inner side of the shapedarticle. This method includes a layer forming process including forminga part of the transparent layer and a part of the decorative layer inthis order from an end side toward a center side of at least two of thelayers.

Two or more of the formed layers have the parts of the transparent layerat positions nearer to the end side than the parts of the decorativelayer. When two or more layers are formed, even if a layer forming inkapplied on the end side of the upper layer drops downward, the layerformed on the end side is the transparent layer, not the decorativelayer. This may avoid loss of the decorative layer inks, successfullyforming a shaped article decorated as desired.

According to this method, a larger formation area including an areaoverlapping a part of the transparent layer in addition to an areaoverlapping a part of the decorative layer in the lower layer may besecured for a part of the decorative layer in the upper layer, ascompared to layers lacking the parts of the transparent layer atpositions nearer to the end side than the parts of the decorative layer.This may help to mitigate a demanded degree of manufacturing accuracy tosome extent, contributing to an improved manufacturing efficiency.

The shaped article manufacturing method disclosed herein according toone aspect is further characterized in that the layer forming processincludes steps of: forming a part of the transparent layer; and forminga part of the decorative layer, wherein the step of forming a part ofthe transparent layer precedes the step of forming a part of thedecorative layer.

According to this method that forms, in a layer, a part of thetransparent layer before a part of the decorative layer, the part of thetransparent layer may serve as the outer moat of the part of thedecorative layer to be later formed. This may prevent the ink applied toform the part of the decorative layer from spreading unintendedly ordropping downward.

The shaped article manufacturing method disclosed herein according toone aspect is further characterized in that one of the layers is newlyformed on another one of the layers formed by the layer forming process,so that a part of the decorative layer in the layer newly formedoverlaps a part of the transparent layer in the layer below previouslyformed.

The shaped article manufacturing method disclosed herein according toone aspect is further characterized in that one of the layers is newlyformed on another one of the layers formed by the layer forming process,so that a part of the transparent layer in the layer newly formedoverlaps a part of the decorative layer in the layer below previouslyformed.

This disclosure may provide a shaped article exhibiting a desired colortone.

An embodiment of a shaped article and a shaped article manufacturingmethod disclosed herein is hereinafter described referring to FIG. 1 toFIG. 8. The shaped article disclosed herein has a three-dimensionalstructure constructed of a laminate of layers (formed by multilayerlamination technique). In the embodiment hereinafter described, inkjetprinting technique is employed to manufacture the shaped article. Thisis, however, just an option presented in this disclosure. Thisdisclosure may be applicable to any kinds of manufacturing methods thatcan obtain a shaped article by leveraging the multilayer laminationtechnique and decorate its surface (recording of characters and imagesin colors).

[1] Structure of Shaped Article

FIG. 1 is a perspective view of an outer shape of a shaped article 50according to an embodiment. The shaped article 50 according to thisembodiment has a substantially cylindrical shape with a curved sidesurface bulging outward. The shaped article disclosed herein and theshaped article manufactured by the manufacturing method disclosed hereinmay not be limited to the shape illustrated in FIG. 1. There are manyother examples of the shape, including a hexahedral shape describedlater, a spherical shape, a hollow structure, a ring-like shape, and ahorseshoe-like shape.

The shaped article 50 according to this embodiment includes a secondtransparent layer, a colored layer (decorative layer) formed fromcolorant-containing inks (decorative ink), a first transparent layerformed from a transparent ink, and a light reflective layer formed froman ink having light reflectiveness, wherein these layers are formed inthe mentioned order from an outer-layer side (outer peripheral side)toward an inner side (center) of the shaped article 50. This is adistinctive technical feature of this disclosure. FIG. 1 is a drawing ofthe shaped article 50. In this drawing, a second transparent layer 4formed from a transparent ink, which is the outermost layer, can be seenon the curved side surface of the shaped article 50.

FIG. 2 is a cross-sectional view of the illustration of FIG. 1 takenalong a cutting-plane line A-A′. The cross-sectional view of the shapedarticle 50 illustrated in FIG. 2 is taken at a central position of theshaped article 50 along the X-Z plane of the XYZ coordinate systemillustrated in FIG. 1.

The embodiment of FIG. 2 presents an example of the shaped article 50having a three-dimensional structure formed by stacking 21 layers 50 aon one another in the Z direction. It should be understood that theshaped article 50 may include less than or more than 21 layers.

[2] Structures of Layers

FIG. 5 is a drawing of the X-Y plane of a layer 50 a in the vicinity ofa mid-stage of the shaped article 50. The layers 50 a each include apart 54 of the second transparent layer, a part 53 of the colored layer,a part 52 of the first transparent layer, and a part 51 of the lightreflective layer. These layers are formed in the mentioned order from anouter peripheral side toward a center side of the shaped article. If theshaped article 50 according to this embodiment is stated another way,the light reflective layer 1, which is the body of the shaped article,is coated with the first transparent layer 2, colored layer 3, andsecond transparent layer 4 in the mentioned order toward the outer-layerside (outer peripheral side). Each one of the layers 50 a has athickness in the Z direction (vertical direction in the drawing) between5 μm and 50 μm. This is an adequate range of thickness values formulticolor formation of the colored layer 3 using the subtractive colormixture. For example, a preferable range of thickness values is 10 μm to25 μm when layers are formed from inks of ultraviolet curing type byinkjet printing technique.

In this embodiment, the light reflective layer 1 is the body of theshaped article; however, the light reflective layer may or may notconstitute the body of the shaped article. Specifically, the shapedarticle may have, at its center, a body or a cavity apart from the lightreflective layer, wherein the light reflective layer, first transparentlayer, colored layer, and second transparent layer are formed in thementioned order from the body (may or may not have light reflectiveness)toward the outer-layer side (outer peripheral side). Alternatively, acore (may or may not have light reflectiveness) and the light reflectivelayer 1 formed on a surface of the core may be collectively regarded asthe body of the shaped article.

By stacking the layers 50 a in the Z direction as illustrated in FIG. 2,the parts 54 of the second transparent layer in the respective layers 50a are substantially continuous in a direction along the outermostsurface of the shaped article 50, forming the second transparent layer4. The parts 53 of the colored layer in the respective layers 50 a aresubstantially continuous in the direction along the outermost surface ofthe shaped article 50, forming the colored layer 3. The parts 52 of thefirst transparent layer in the respective layers 50 a are substantiallycontinuous in the direction along the outermost surface of the shapedarticle 50, forming the first transparent layer 2. The parts 51 of thelight reflective layer in the respective layers 50 a are substantiallycontinuous in the direction along the outermost surface of the shapedarticle 50, forming the light reflective layer 1.

Looking at, in any of the X, Y, and Z directions, the outer surface ofthe shaped article 50 including the second transparent layer, coloredlayer, first transparent layer, and light reflective layer arranged inthe mentioned order, a color tone produced by the subtractive colormixture may be visually recognized.

The parts 52 of the first transparent layer may preferably have adimension in the direction of X-Y plane slightly greater than the part53 of the colored layer vertically in contact with the parts 52. Thismay more reliably prevent intermixing of the inks forming the coloredlayer 3 and the light reflective layer 1.

The parts 54 of the second transparent layer may preferably have adimension in the direction of X-Y plane slightly greater than the parts53 of the colored layer vertically in contact with the parts 54. Thismay provide for better protection of the colored layer 3.

The width of the shaped article 50 along the Z direction (hereinaftermay be referred to as thickness or height in the Z direction) is notparticularly limited. The thickness (height) of the layer 50 a in the Zdirection may be optionally decided depending on the number of layers.As described later, this embodiment constructs the multilayeredstructure using the inkjet printing technique. Therefore, any feasiblevalues in the technique should be contemplated for the thickness of thelayer 50 a in the Z direction. When inks of ultraviolet curing type areapplied by inkjet printing technique to form the layers (describedlater), the layer 50 a may have a thickness ranging from 5 μm to 20 μmdepending on the sizes of ink droplets. As for a large-sized shapedarticle for which a high resolution is not particularly required, plurallayers may be formed based on the same data simply by increasing thesizes of ink droplets. In such a case, a smaller data volume and ahigher molding rate may be anticipated.

[3] Structure of Light Reflective Layer 1 (Parts 51 of Light ReflectiveLayer)

The light reflective layer 1 (parts 51 of the light reflective layer) isa layer formed from a light reflective ink. This layer, therefore, haslight reflectiveness that allows rays of light in the whole visiblelight region to be reflected on at least the surface of the lightreflective layer 1 in contact with the colored layer.

Specific examples of ink of the light reflective layer 1 (parts 51 ofthe light reflective layer) may include metallic powder-containing inksand white pigment-containing inks. The light reflective layer 1 maypreferably be forming from a white ink. The light reflective layer 1formed from a white ink may adequately reflect rays of light enteringfrom the outer-layer side of the shaped article, allowing the shapedarticle to be colored by the subtractive color mixture.

In this embodiment, the light reflective layer 1 constitutes the body ofthe shaped article. In case the light reflective layer 1 is formed onthe surface of the body of any shaped article for which lightreflectiveness is not required, the thickness of the light reflectivelayer 1, i.e., the width of the part 51 of the light reflective layerfrom the outer peripheral side to the center side, as illustrated inFIG. 2, may be between 5 μm and 20 μm at the least. The width in thisdisclosure may include but is not limited to the range of values.

[4] Structure of First Transparent Layer 2 (Parts 52 of FirstTransparent Layer)

The first transparent layer 2 (parts 52 of the first transparent layer)is formed from a transparent ink.

The transparent ink may refer to an ink capable of forming a transparentlayer having light transmittance greater than or equal to 50% per unitthickness. The light transmittance less than 50% per unit thickness ofthe transparent layer may unintendedly block the transmission of light.This may be a drawback that fails to exhibit a desired color tone of theshaped article by way of the subtractive color mixture. Preferably isused an ink having light transmittance greater than or equal to 80% perunit thickness of the transparent layer. Further, an ink having lighttransmittance greater than or equal to 90% per unit thickness of thetransparent layer is particularly preferable.

By interposing the first transparent layer 2 (part 52 of the firsttransparent layer) between the light reflective layer 1 (part 51 of thelight reflective layer) and the colored layer 3 (part 53 of the coloredlayer), intermixing of the coloring inks of the colored layer 3 and theink of the light reflective layer 1 may be avoidable. Even if thecoloring inks applied to form the colored layer are mixed with thetransparent ink of the first transparent layer, intermixing of theseinks may not adversely affect colors of the colored layer or cause anyundesirable change to the color tone. Therefore, the resulting shapedarticle exhibits a desired color tone (decorated as desired) expressedby the colored layer 3.

The width of the part 52 of the first transparent layer from the outerperipheral side to the center side (hereinafter, referred to as thethickness of the first transparent layer) is between 5 μm and 20 μm atthe least in a decorated portion on a surface perpendicular to thelayer-stacked direction. The width in this disclosure may include but isnot limited to the range of values.

[5] Structure of Colored Layer 3 (Part 53 of Colored Layer)

The colored layer 3 (part 53 of the colored layer) is formed from acolorant-containing coloring ink.

Examples of the colorant-containing inks (hereinafter may be referred toas coloring ink) may include but are not limited to yellow (Y), magenta(M), cyan (C), black (K), and pale color inks. Further, red (R), green(G), blue (B), and orange (Or) color inks may be additionally used.Other usable inks may include metallic, pearl, and phosphor inks. One ormore than one of these coloring inks may preferably be used to express adesired color tone.

The amounts of the coloring inks to form the colored layer 3 (parts 53of the colored layer) may be variable depending on a desired (desirablyexpressed) color tone. In case the coloring inks alone are used toexpress a bright color tone at a relatively low concentration, the inkdensity of the colored layer 3 may fail to meet a predetermined inkdensity. This may generate irregularities in the Z direction and/orink-less dented parts at positions along the X-Y direction. In any case,the shaped article formed by the multilayer lamination technique, asdescribed in this embodiment, may consequently have an irregular,unattractive shape, which is desirably avoided. In case onecross-sectional surface of the colored layer 3 has the ink density oftwo lateral and two vertical ink droplets; four ink droplets in total,formed by the error diffusion method on a vertical mold surface near themid position of the multilayered structure illustrated in FIG. 2, thecoloring inks each form four ink droplets at the most (largestconcentration) and no ink droplet at the least (zero concentration,meaning colorless). The number of ink droplets being zero may leave anunfilled space as large as four ink droplets, significantly degradingthe shaped article in view of its shape and color tone.

This embodiment, therefore, fills the ink density of the colored layer 3(part 53 of the colored layer) using a supplementary ink in parts of thecolored layer 3 (part 53 of the colored layer) in which the coloringinks alone are insufficient to meet a predetermined ink density.Specifically, the colored layer 3 (parts 53 of the colored layer) isformed at a constant total density (number of ink droplets) of thecoloring inks and the supplementary ink. This may successfully preventthe formation of dented parts, allowing the shaped article 50 to beelaborately shaped.

The amounts of the coloring inks to be discharged and their landingpositions are known beforehand, based on which the amount and position(landing position) of the supplementary ink to be additionallydischarged may be suitably determined. The amount and position may bedecided by an inkjet head device 10 or by a controller not illustratedin the drawings.

Having the ink density filled by the supplementary ink may allow asurface formed by the colored layer 3 to be flattened, impartingglossiness to the surface.

The supplementary ink may be any ink unless it adversely affects thecolor tone to be expressed by the colored layer 3 (parts 53 of thecolored layer). An example of the supplementary ink may be thetransparent ink used to form the first transparent layer 2 (parts 52 ofthe first transparent layer) and the second transparent layer 4 (parts54 of the second transparent layer).

The thickness of the colored layer 3, i.e., the width of the part 53 ofthe colored layer from the outer peripheral side to the center sideillustrated in FIG. 2 (hereinafter, referred to as the thickness of thecolored layer 3) may be between 5 μm and 20 μm.

The colored layer 3 described in this embodiment is just an option andmay be any decorative layer.

[6] Structure of Second Transparent Layer 4 (Parts 54 of SecondTransparent Layer)

The second transparent layer 4 (parts 54 of the second transparentlayer) is formed from the same transparent ink as that of the firsttransparent layer 2 (parts 52 of the first transparent layer). The sametransparent ink or different transparent inks may be used to form thesecond transparent layer 4 and the first transparent layer 2.

The thickness of the second transparent layer 4, i.e., the width of thepart 54 of the second transparent layer from the outer peripheral sideto the center side illustrated in FIG. 2 (hereinafter, referred to asthe thickness of the second transparent layer 4) may be between 10 μmand 100 μm.

The second transparent layer 4 functions as a protective layer for thecolored layer 3. In this disclosure that employs the multilayerlamination technique (this embodiment), the second transparent layer 4may also advantageously contribute to elaborateness of the shapedarticle.

Supposing that the colored layer 3 is the outermost layer of the shapedarticle 50, i.e., the parts 53 of the colored layer are located at thefarthest ends of the respective layers 50 a illustrated in FIG. 2, thecolored layer 3 (parts 53 of the colored layer) formed may not be asaccurate as expected. On the other hand, the shaped article 50 whoseoutermost layer is the second transparent layer 4 (parts 54 of thesecond transparent layer), as described in this embodiment, may ensurethe accuracy of the colored layer 3 (parts 53 of the colored layer).Thus, the second transparent layer 4 (parts 54 of the second transparentlayer) may greatly contribute to a desired color tone.

Another disadvantage in case the colored layer 3 is the outermost layerof the shaped article 50 is that the exposed colored layer 3 may beprone to decolorization under friction and color fading by exposure toultraviolet. However, as described in this embodiment, the shapedarticle 50 whose outermost layer is the second transparent layer 4(parts 54 of the second transparent layer) may prevent such unfavorableevents as decolorization and color fading.

[7] Manufacturing Method for Shaped Article

A manufacturing method for the shaped article 50 according to thisembodiment is hereinafter described. FIG. 3 is a drawing of the lowersurface of the inkjet head device 10 used in the manufacturing method.FIG. 4 shows schematic drawings of ongoing steps of manufacturing theshaped article 50 according to this embodiment.

The inkjet head device 10 has, on its lower surface, roughly threeinkjet heads 11H to 13H. As illustrated in FIG. 3, the first inkjet head11H, second inkjet head 12H, and third inkjet head 13H are displacedfrom one another in the X direction. As illustrated in FIG. 3, the firstinkjet head 11H, second inkjet head 12H, and third inkjet head 13H arealso displaced from one another in the Y direction. Thus, the inkjetheads 11H to 13H are positioned in, generally called, staggeredarrangement.

The first inkjet head 11H has a cyan ink nozzle 10 (C) for discharging acyan ink, a magenta ink nozzle 10 (M) for discharging a magenta ink, ayellow ink nozzle 10 (Y) for discharging a yellow ink, and a black inknozzle 10 (K) for discharging a black ink. The number and the order ofarrangement of the nozzles 10 (C), 10 (M), 10 (Y), and 10 (K) are notlimited to the example illustrated in FIG. 3. All of the inks dischargedthrough these nozzles are coloring inks used to form the colored layer 3(parts 53 of the colored layer) illustrated in FIG. 2.

The second inkjet head 12H has a white ink nozzle 10 (W) for discharginga white ink (W). The white ink (W) is an ink used to form the lightreflective layer 1 (parts 51 of the light reflective layer) illustratedin FIG. 2.

The third inkjet head 13H has a transparent ink nozzle 10 (CL) fordischarging a transparent ink (CL). The transparent ink (CL) is an inkused to form the first transparent layer 2 (parts 52 of the firsttransparent layer) and the second transparent layer 4 (parts 54 of thesecond transparent layer) illustrated in FIG. 2.

The inkjet head device 10 is located so as to have its lower surfaceillustrated in FIG. 3 face the layer 50 a currently being formed. Theinkjet head device 10 is configured to reciprocate in the X directionand discharge the inks while moving in the direction. The inkjet headdevice 10 is moved in a predetermined direction in an XYZ coordinatesystem, or a table with the formed layers 50 a placed thereon (FIG. 4shows a layer formation surface B of the table) is moved in apredetermined direction in the XYZ coordinate system to change relativepositions of the inkjet head device 10 and the layer 50 a currentlybeing formed. Which one of them should be moved may be optionallydecided.

Each of the inks is an ink of ultraviolet curing type that needs to beirradiated with ultraviolet light after being discharged. A ultravioletirradiator may be mounted in the inkjet head device 10 or may beinstalled as a separate device. The inks are cured by being irradiatedwith ultraviolet light to form the layers 50 a illustrated in FIG. 2.

The manufacturing process for the shaped article 50 using the inkjethead device 10 is hereinafter described referring to FIG. 4.

To start with, a first one of the layers 50 a (first layer 50 a (1)) isformed on the layer formation surface B of the table.

In the step of forming (manufacturing) the first layer 50 a (1), byusing the inkjet printing technique, the respective inks are dischargedfrom the inkjet head device 10 at predetermined timings to form a partof the second transparent layer, a part of the colored layer, a part ofthe first transparent layer, and a part of the light reflective layer inthe mentioned order from the end side toward the center side of thefirst layer 50 a.

The steps of forming (manufacturing) the first layer 50 a (1) aredescribed in further detail referring to (a)˜(c) of FIG. 4.

In step S1 illustrated in (a) of FIG. 4, the part 54 of the secondtransparent layer is formed from the transparent ink, and the part 52 ofthe first transparent layer is formed from the transparent ink. In thisstep, the inkjet head device 10 is moved in a positive direction alongthe X axis, and the transparent ink is discharged at a predeterminedtiming through the transparent ink nozzle 10 (CL) illustrated in FIG. 3.The discharged ink lands on a position at which the part 54 of thesecond transparent layer should be formed and a position at which thepart 52 of the first transparent layer should be formed. Then, thedischarged ink pooled at the respective positions is irradiated withultraviolet light to be cured. As a result, the part 52 of the firsttransparent layer and the part 54 of the second transparent layer areformed as illustrated in (a) of FIG. 4.

In step S2 illustrated in (b) of FIG. 4, the inkjet head device 10 ismoved in a negative direction along the X axis, and the white ink (W),which is the light reflective ink, is discharged at a predeterminedtiming through the white ink nozzle 10 (W). Then, the discharged inkpooled there is irradiated with ultraviolet light to be cured. As aresult, the part 51 of the light reflective layer is formed asillustrated in (b) of FIG. 4.

In step S3 illustrated in (c) of FIG. 4, the inkjet head device 10 ismoved in the positive direction along the X axis, and the colored layerforming inks including the coloring inks and the supplementary ink aredischarged at a predetermined timing so that the total amount of theseinks discharged is constant, and then irradiated with ultraviolet light.The predetermined timing refers to a timing at which the nozzles of thefirst inkjet head 11H are located at positions at which the coloredlayer forming inks are dischargeable in a region between the part 52 ofthe first transparent layer and the part 54 of the second transparentlayer formed in step S1. The ink droplets in a predetermined amount aredischarged by inkjet printing technique at this timing to form a pool ofink. Then, the pooled ink is irradiated with ultraviolet light to becured. This forms the part 53 of the colored layer 53 exhibiting adesired color tone between the part 52 of the first transparent layerand the part 54 of the second transparent layer as illustrated in (c) ofFIG. 4.

As a result of steps S1 to S3, the formation of the first layer 50 a (1)is completed. The first layer 50 a (1) has the same structure asillustrated in the upper view of the layer 50 a in FIG. 5. Optionally,step 1 and step 2 may be performed in the reversed order. Likewise, stepS2 and step S3 may be performed in the reversed order.

After the first layer 50 a (1) is formed, a new layer 50 a (second layer50 a (2)) is formed on the first layer 50 a (1) (laminate of layers).

In the shaped article 50 according to this embodiment, the layers 50 astacked on one another are progressively increased in size (area) fromthe bottom toward the mid stage of the multilayered body as illustratedin FIG. 2. In the shaped article 50 manufactured in such a shape thatincreases in size along the layer-stacked direction when viewed in crosssection, the end of one layer 50 a is sticking out sideways further thanthe end of another layer 50 a already formed below the one layer 50 a.To form the layers 50 a thus characterized, support material layers maypreferably be formed.

In FIG. 4, (d) is a drawing of the step of forming the second layer 50 a(2). Referring to this drawing, a part 53 (2) of the colored layer inthe second layer 50 a (2) is formed so as to overlap a part 54 (1) ofthe second transparent layer in the first layer 50 a (1). Since thesecond layer 50 a (2) is greater in size (area) along the X-Y plane thanthe first layer 50 a (1), the part 54 (2) of the second transparentlayer forming the end of the second layer 50 a (2) is sticking outsideways further than the part 54 (1) of the second transparent layerforming the end of the first layer 50 a (1). Because of this structure,the ink to be deposited on a part of the layer 50 a (2) where thestick-out part should be formed possibly runs off this part and dropsdownward. To avoid that, a support material 60 is formed on the outerside (on the lateral side) than the part 54 (1) of the secondtransparent layer in the first layer 50 a (1).

The support material 60 may preferably be formed from any ink that canbe discharged by inkjet printing technique. The support material 60should preferably have enough strength not to collapse under the weightof another layer formed thereon. The support material 60 per se will notbe left in the finalized shaped article 50. The ink forming the supportmaterial 60, therefore, should preferably be selected from inks that canbe stripped off afterwards. The ink of the support material 60 maypreferably be curable by ultraviolet light (to a degree of cure at whichthe ink is stripped off in subsequent steps), or may be a water-solubleink that can be dissolved in water and removed in subsequent steps.

The steps of forming the layers 50 a are repeatedly performed in the Xand Y directions as many times as required to form one layer, and thenrepeatedly performed again in the Z direction. As a result, the shapedarticle 50 illustrated in FIG. 2 is finally obtained. During the stepsof forming one layer, the known interlace scan conventionally employedto form two-dimensional images may preferably be performed to obtain ashaped article with less unevenness in shape and favorably decorated.

The shaped article manufacturing method according to this embodiment isfurther characterized in that the layer forming process includes stepsof: forming the part 54 of the second transparent layer using thetransparent ink; forming the part 53 of the colored layer using thecoloring inks; forming the part 52 of the first transparent layer usingthe transparent ink; and forming the part 51 of the light reflectivelayer using the light reflective ink, wherein the step of forming thepart 53 of the colored layer is performed subsequent to the step offorming the part 52 of the first transparent layer and the step offorming the part 54 of the second transparent layer to form the part 53of the colored layer between the part 52 of the first transparent layerand the part 54 of the second transparent layer. When the part 53 of thecolored layer is formed, the part 54 of the second transparent layer mayserve as the outer moat of the pooled inks to form the colored layer.This may prevent the ink of the colored layer from spreadingunintendedly, ensuring a high accuracy of the part 53 of the coloredlayer.

Further benefits delivered by forming the part 54 of the secondtransparent layer are described referring to FIG. 6 and FIG. 7. FIG. 6is a drawing of a part of the shaped article 50 according to thisembodiment, which is the part of (d) of FIG. 4 from which the supportmaterial has been removed. FIG. 7 is a cross-sectional view of a shapedarticle for comparison. The shaped article for comparison is formed bythe multilayer lamination technique similarly to the shaped article 50according to this embodiment. Unlike the shaped article 50, however,this shaped article lacks parts corresponding to the part 52 of thefirst transparent layer and the part 54 of the second transparent layer.In this shaped article for comparison, therefore, the light reflectivelayer is directly coated with the colored layer. Provided that the upperlayer is larger in size (area) along the X-Y plane than the lower layerin the shaped article for comparison, problems with this shaped articleare described.

In the shaped article for comparison illustrated in FIG. 7, the end ofthe upper layer includes a colored layer 152 (2). The colored layer 152(2) is sticking out further than a colored layer 152 (1) formed on theend of the lower layer. This shaped article, therefore, involves therisk that the inks for the colored layer discharged to form thestick-out part run off a coloring position and drop downward.

The colored layer is the deciding factor for the color tone of theshaped article. Therefore, thus losing the inks of the colored layer maycause an intended color tone of the shaped article to change.

On the other hand, the shaped article 50 according to this embodimentillustrated in FIG. 6 has the parts 54 of the second transparent layerat the ends of the layers 50 a. The ink applied to form the parts 54 ofthe second transparent layer, even if it falls downward in FIG. 6, maynot adversely affect a color tone desirably expressed because thecolored layer is the deciding factor for the color tone. This embodimentmay thus successfully manufacture the shaped article 50 that excels inreliability and exhibits a desired color tone.

There are other benefits as well. One of them is, forming the part 54 ofthe second transparent layer in the first layer 50 a (1) allow a largerformation area to be secured for the colored layer of the second layer50 a (2). This may help to mitigate a demanded degree of manufacturingaccuracy to some extent, conducing to an improved manufacturingefficiency.

The ability to secure a larger formation area is advantageouslyeffective even if the part 54 of the second transparent layer is formedsubsequent to the part 53 of the colored layer. This disclosure,therefore, further includes forming the part 54 of the secondtransparent layer subsequent to the part 53 of the colored layer.

In the shaped article 50 according to this embodiment, the surface ofthe colored layer 3 is coated with the second transparent layer 4. Thesecond transparent layer 4 thus serves as the protective layer of thecolored layer 3.

FIG. 4 illustrates an example in which the upper layer is greater insize (area) along the X-Y plane than the lower layer. This examplerefers to the lower half of the shaped article 50 of FIG. 1 split in twohalves.

The manufacturing method described so far is basically applicable to theupper-half structure of the shaped article 50 of FIG. 1 split in twohalves. As for the upper half of the shaped article 50, as illustratedin FIG. 2, the upper colored layer is nearer to the center side of thelayer 50 a than the lower colored layer, and the parts 53 of the uppercolored layer overlap the parts 52 of the lower first transparent layer.Further, the parts 54 of the upper second transparent layer overlap theparts 53 of the lower colored layer.

In the upper half of the shaped article 50, as illustrated in FIG. 2,the lower layers are greater in size (area) along the X-Y plane than theupper layers formed thereon. In this upper-half structure, the inkapplied to form the colored layer in the upper layers is very unlikelyto drop downward. No support material may be necessary at the time ofmanufacturing the upper-half structure.

In the shaped article of FIG. 2 according to this embodiment, the bottomlayer and layers nearby, and the top layer and layers nearby include: alayer solely having the part 52 of the first transparent layer, part 53of the colored layer, and part 54 of the second transparent layer; alayer solely having the part 53 of the colored layer and the part 54 ofthe second transparent layer; and a layer solely having the part 54 ofthe second transparent layer. This multilayered structure may effectuatea shaped article whose entire surface is covered with the secondtransparent layer 4, colored layer 3, and first transparent layer 2.This disclosure, however, is not limited to such a structure. Forexample, the top and bottom surfaces of the shaped article may includenone of the second transparent layer, colored layer, or firsttransparent layer.

[8] Modified Example First Modified Example

The shaped article 50 according to this embodiment includes the firsttransparent layer 2, colored layer 3, and second transparent layer 4that are formed along the surface of the light reflective layer 1.However, this disclosure may include but is not limited to such astructure, and may optionally have a shaped article illustrated in FIG.8.

In the shaped articles illustrated in (a)˜(d) of FIG. 8, the secondtransparent layer 4 may have a shape described below instead of theshape along the surface of the light reflective layer 1. Because theparts 54 of the second transparent layer constitute the ends of thelayers 50 a (FIG. 2), the second transparent layer 4 may be formed in anadequate shape that contains therein the shaped article (structuredescribed in the earlier embodiment including the colored layer 3, firsttransparent layer, and light reflective layer), as illustrated in(a)˜(d) of FIG. 8.

Containing the shaped article in the shape formed by the secondtransparent layer 4, as described in this first modified example, may beuseful for any shaped articles that are mechanically fragile. Forexample, this modified example may be effectively applicable when, forexample, molding insects' legs and wings, and stems and petals offlowering plants. When molding organisms and plants in the form ofdecorative ornaments or specimens, they can be scanned alive by athree-dimensional scanner and released again into the nature when themolding is over. A further benefit may be eco-friendliness because nosupport material is necessary, producing no waste material.

In the shaped article illustrated in (a) of FIG. 8, the secondtransparent layer 4 has a hexahedral shape that contains a sphericalbody including the colored layer 3, first transparent layer, and lightreflective layer. The structure illustrated in (a) of FIG. 8 may beobtained by a manufacturing method similar to the method of FIG. 4.

In FIG. 8, (b) illustrates a shaped article 50 of frame-mounted type,wherein a figure including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4. This is a free-standing shaped article 50 supported by the secondtransparent layer 4. This shaped article 50 of frame-mounted type may bemanufactured (fabricated) by the manufacturing method described in theearlier embodiment.

In FIG. 8, (c) illustrates a shaped article 50 for use as a strap,wherein a figure including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4, and a hole 70 is formed in a part of the second transparent layer 4.This may be used as a strap or a key holder attachable to, for example,a mobile telephone. The hole 70 of the second transparent layer 4 may beformed at the same time when the outer shape is formed by the secondtransparent layer 4. By punching a hole in the second transparent layer4, the figure including the colored layer 3, first transparent layer,and light reflective layer can avoid being damaged with a hole.

In the shaped article 50 illustrated in (d) of FIG. 8, the upper-half ofa figure's body including the colored layer 3, first transparent layer,and light reflective layer is contained in the second transparent layer4. This article 50 has, on the surface or inside of the secondtransparent layer 4, a three-dimensional image 71 decorated with a markor a frame or painted in a pale color. This shaped article 50 furtherhas, on the surface or inside of the second transparent layer 4, aletter/character area 72 with letters and/or characters representingdate, name, or place. The decorated three-dimensional image 71 and theletter/character area 72 may be formed at the same time when the outershape is formed by the second transparent layer 4. Instead of thedecorated three-dimensional image 71 and the letter/character area 72,other additional information may be displayed on the surface or insideof the second transparent layer 4.

In (b)˜(d) of FIG. 8, one figure is contained in the second transparentlayer 4, however, the number of figures containable in the secondtransparent layer 4 may be other than one.

In case the shaped article according to this embodiment has a ring-likeshape, the colored layer may be formed near an inner peripheral end ofthe ring shape as well as an outer peripheral end thereof. Inconclusion, the colored layer may be formed on the surface of the shapedarticle, and the second transparent layer may be further formed thereon.

Instead of forming the second transparent layer 4 in any desired shapeas described in this modified example, the second transparent layer 4may be formed in a shape suitable for the surface of the lightreflective layer 1 similarly to the earlier embodiment. In that case,the obtained shaped article may be sealed in an optionally-shaped resin.

Second Modified Example

In the embodiment described earlier, the shaped article 50 ismanufactured by the inkjet head device 10 illustrated in FIG. 3. Insteadof the inkjet head device 10, inkjet head devices illustrated in FIG.10, FIG. 12, FIG. 13, and FIG. 14 may be used.

FIG. 10 is a drawing of a modified example of the inkjet head device,illustrated similarly to FIG. 3. The inkjet head device 10′ illustratedin FIG. 10 has, on its lower surface, roughly two inkjet heads 11H′ and12H′. As illustrated in FIG. 10, the first inkjet head 11H′ and thesecond inkjet head 12H′ are displaced from each other in both of the Xand Y directions. The first inkjet head 11H′ is the same as the firstinkjet head 11H illustrated in FIG. 3. The second inkjet head 12H′includes a white ink nozzle 10 (W) for discharging a white ink (W) usedto form the light reflective layer 1 (parts 51 of the light reflectivelayer), and a transparent ink nozzle 10 (CL) for discharging atransparent ink (CL).

FIG. 12 is a drawing of another modified example of the inkjet headdevice, illustrated similarly to FIG. 3. In an inkjet head device 10 aillustrated in FIG. 12, a cyan ink nozzle 10 (C), a magenta ink nozzle10 (M), a yellow ink nozzle 10 (Y), a black ink nozzle 10 (K), a whiteink nozzle 10 (W), and a transparent ink nozzle 10 (CL) are arranged inthe mentioned order in the X direction.

FIG. 13 is a drawing of yet another modified example of the inkjet headdevice, illustrated similarly to FIG. 3. In an inkjet head device 10 billustrated in FIG. 13, a white ink nozzle 10 (W), a transparent inknozzle 10 (CL), a yellow ink nozzle 10 (Y), a magenta ink nozzle 10 (M),a cyan ink nozzle 10 (C), a black ink nozzle 10 (K), a transparent inknozzle 10 (CL), and a white ink nozzle 10 (W) are arranged in thementioned order in the X direction.

FIG. 14 is a drawing of yet another modified example of the inkjet headdevice. An inkjet head device 10 b illustrated in FIG. 14 has a carriage21 allowed to reciprocate along the X axis, a plurality of nozzle arraysmounted in the carriage 21, and ultraviolet irradiators 24 a and 24 bmounted in the carriage 21. The carriage 21 is moved in the Y directionto perform a scan, in which the inks of ultraviolet curing type aredischarged from the nozzle arrays and irradiated with ultraviolet lightemitted from the ultraviolet irradiators 24 a and 24 b.

The nozzle arrays are aligned along the X direction as illustrated inFIG. 14. From the left to right in the X direction on the drawing, acyan ink nozzle array C, a magenta ink nozzle array M, a yellow inknozzle array Y, a black ink nozzle array K, a white ink nozzle array W,and a transparent ink nozzle array CL are aligned in the mentionedorder. Since the nozzle arrays are mounted in the carriage 21, the inksof ultraviolet curing type are dischargeable from these nozzle arrayswhile moving in the X direction with the carriage 21.

Because all of the nozzles are aligned in the X direction in FIG. 12,FIG. 13, and FIG. 14, the formation of one layer may be completed bymoving the nozzles once in the X direction and discharging all of therequired ink during the movement. Referring to FIG. 14, since all of theinks may be discharged and irradiated with ultraviolet light by movingthe nozzles just once in the X direction, a layer formed from the inksof ultraviolet curing type may be cured as soon as the inks aredischarged.

[Additional Remarks]

A shaped article 50 according to one aspect includes: a light reflectivelayer 1 formed from a light reflective ink; a colored layer 3; and asecond transparent layer 4 formed from a transparent ink, wherein thecolored layer 3 is formed on an outer side of the light reflective layer1, and the second transparent layer 4 is formed on an outer side of thecolored layer 3.

In this shaped article, a larger formation area including an areaoverlapping the part 54, 54 (2) of the second transparent layer inaddition to an area overlapping the part 53, 53 (1) of the colored layerin the lower layer may be secured for the part 53, 53 (2) of the coloredlayer in the upper layer, as compared to layers lacking the parts 54 ofthe second transparent layer at positions nearer to the end side thanthe parts 53 of the colored layer. This may help to mitigate a demandeddegree of manufacturing accuracy to some extent, contributing to animproved manufacturing efficiency.

The manufacturing method for the shaped article 50 according to oneaspect is a manufacturing method for forming the shaped article 50 bystacking a plurality of layers 50 a on one another, the shaped article50 including a second transparent layer 4 formed from a transparent ink;and a colored layer 3, wherein the second transparent layer 4 and thecolored layer 3 are formed in this order from an outer-layer side towardan inner side of the shaped article 50. This method includes a layerforming process including forming the parts 54 of the second transparentlayer and the parts 53 of the colored layer in this order from an endside toward a center side of at least two of the layers 50 a.

According to the manufacturing method wherein the parts 54 of the secondtransparent layer are formed at positions nearer to the end side thanthe parts 53 of the colored layer, the ink applied to form the parts 54of the second transparent layer, if dropping downward from positions atwhich the parts 54 should be formed during the manufacturing process,may be unlikely to adversely affect the color tone, because it is thecolored layer 3 (parts 53 of the colored layer) that decides the colortone. This method may thus successfully manufacture the shaped article50 that excels in reliability and exhibits a desired color tone(decorated as desired).

According to this method, a larger formation area including an areaoverlapping the part 54, 54 (2) of the second transparent layer inaddition to an area overlapping the part 53, 53 (1) of the colored layer3 in the lower layer may be secured for the part 53, 53 (2) of thecolored layer 3 in the upper layer, as compared to layers lacking theparts 54 of the second transparent layer at positions nearer to the endside than the parts 53 of the colored layer. This may help to mitigate ademanded degree of manufacturing accuracy to some extent, contributingto an improved manufacturing efficiency.

The shaped article manufacturing method according to one aspect isfurther characterized in that the layer forming process includes stepsof: forming the part 54 of the second transparent layer; and forming thepart 53 of the colored layer, wherein the step of forming the part 54 ofthe transparent layer precedes the step of forming the part 53 of thecolored layer.

According to this method that forms the part 54 of the secondtransparent layer in one layer 50 a before the part 53 of the coloredlayer, the part 54 of the second transparent layer may serve as theouter moat of the part 53 of the colored layer to be later formed. Thismay prevent the ink applied to form the part 53 of the colored layerfrom spreading unintendedly or dropping downward.

The shaped article manufacturing method disclosed herein according toone aspect is further characterized in that one of the layers 50 a isnewly formed on another one of the layers 50 a by the layer formingprocess, so that the part 53 of the colored layer in the layer 50 anewly formed overlaps the part 54 of the second transparent layer in thelayer 50 a previously formed.

The shaped article manufacturing method disclosed herein according toone aspect is further characterized in that one of the layers 50 a isnewly formed on another one of the layers 50 a by the layer formingprocess, so that the part 54 of the second transparent layer in thelayer 50 a newly formed overlaps the part 53 of the colored layer in thelayer 50 a previously formed.

This disclosure is not necessarily limited to the embodiment describedso far and may be carried out in many other forms. The technical scopeof this disclosure encompasses any modifications within its scopedefined by the appended claims and embodiments obtained by variouslycombining the technical means disclosed herein. By variously combiningthe technical means disclosed in the embodiment and modified examples,additional technical features may be further presented.

INDUSTRIAL APPLICABILITY

This disclosure may be applicable to shaped article manufacturingmethods and manufacturing apparatuses for implementing the methods. Thisdisclosure is particularly useful in manufacturing a three-dimensionalshaped article decorated as desired, for example, decorated in fullcolors.

1. A manufacturing method for a shaped article, the shaped articlecomprising: a decorative layer; a first transparent layer; and a lightreflective layer, being formed from an ink having light reflectiveness,the decorative layer, the first transparent layer, and the lightreflective layer being formed in this order from an outer-layer sidetoward an inner side of the shaped article, wherein the manufacturingmethod for the shaped article employs multilayer lamination technique toform layers and comprises a layer forming process, and the layer formingprocess including: forming a part of the decorative layer, a part of thefirst transparent layer, and a part of the light reflective layer inthis order from an end side toward a center side of each one of thelayers.
 2. The manufacturing method for a shaped article according toclaim 1, wherein the layer forming process comprises: forming a secondtransparent layer using a transparent ink on the outer-layer side of thedecorative layer by forming a part of the second transparent layer at aposition nearer to the end side than a part of the decorative layer. 3.The manufacturing method for a shaped article according to claim 2,wherein the layer forming process includes steps of: forming a part ofthe decorative layer; forming a part of the first transparent layerusing a transparent ink; forming a part of the light reflective layerusing an ink having light reflectiveness; and forming a part of thesecond transparent layer using a transparent ink, wherein themanufacturing method for the shaped article comprises: performing thestep of forming a part of the decorative layer, which is subsequent tothe step of forming a part of the first transparent layer and the stepof forming a part of the second transparent layer, to form a part of thedecorative layer between a part of the first transparent layer and apart of the second transparent layer.
 4. The manufacturing method for ashaped article according to claim 2, further comprising: providing, in aportion of a region with no overlap between a part of the decorativelayer in one of the layers and a part of the decorative layer in anotherone of the layers on or below the one of the layers, an overlap betweena part of the decorative layer in one of the layers and a part of thefirst transparent layer or a part of the second transparent layer inanother one of the layers on or below the one of the layers.
 5. Themanufacturing method for a shaped article according to claim 1, whereinthe step of forming a part of the decorative layer comprises: forming apart of the decorative layer by filling an ink density of the decorativelayer using a transparent supplementary ink in a part of the decorativelayer in which decorative inks alone are insufficient to meet apredetermined ink density.